In a sprawling studio in suburban Mumbai, a sundry crowd of invitees listens as a harried production assistant puts them through their paces. He demonstrates the countdown, the routine of the cheering, and the selection process. Only some of them, as in all TV shows, will share centre stage with the host.

Elsewhere, another harried assistant is haranguing a make-up artist as she finishes with Madhuri Dixit, star anchor of the show Shubh Vivah (Happy Marriage). Dixit, now past her prime, was once the ultimate symbol of Indian female sensuality, the prima donna of the Bollywood blockbuster. After several years in high orbit as a leading star, she returned to terra firma some months ago when she wedded, in a traditional Hindu arranged marriage, a cardiac surgeon from her own community.

Dixit's show is an extension of the classic matrimonial adverts that fill newspapers such as the India Express: "UK citizen, 30, 5ft 8ins, 65kg, fair, handsome, professional with Ernst & Young. Invite offers from slim, pretty, fair graduate, computer background preferred. No dowry." Or: "Alliance invited for Kamma Naidu boy, fair, 31, 5ft 5ins, software engineer working in Singapore, from Kamma Naidu girl, fair, BE, MCA, 23-28 years."

Women who wish to marry apply to feature on Dixit's show (and the many copycats it has spawned). The programme goes out on Sunday mornings, and as the contestants banter with the anchor they list the attributes of their ideal spouse. Men who are watching then get in touch . . . On occasion, proposals have come from the audience itself. Ratings are soaring and the strike rate is high.

The shows derive from an ancient Hindu idea - the swayamvar. In the pristine past, young women chose their grooms from eligible bachelors lined up before them. This would be an open-air daytime event, quite often a public spectacle, complete with sacred fire and the chanting of Vedic hymns by bare-torsoed Brahmin priests. Sometimes, there would be a competition to test the suitor; here, the woman did not have a choice - the winner took her. The god-prince Rama won Sita in the epic Ramayana by stringing a gigantic bow.

History also records the dramatic abduction in the 12th century of Princess Sanyogita from her swayamvar by Prithviraj Chauhan, the last Hindu ruler of Delhi. Her father did not approve of the alliance. The apocryphal story has the Chauhan order a bronze image of himself and place it at the far end of the row of suitors. He hides behind the statue. The cheeky princess garlands the statue - and on cue, the gallant prince, a la Lochinvar, scoops up the princess and rides off into the azure sunset of the Aravalli hills on his faithful steed.

The swayamvar is no longer in vogue in India today; arranged marriages are the principal vehicles of matrimonial union. Mira Nair's Monsoon Wedding typically captures the delicate but wholly comfortable balance between modern, western notions of freedom of choice and the "daddy knows best" syndrome. Boy and girl will meet and talk; the meeting may be held on neutral territory such as a cafe or a friend's home. Parents need not attend, and if boy and girl agree, they plan the wedding. Once the engagement is announced, most taboos are lifted and a relationship may actually begin. The situation is very different from the one they would have found themselves in, even a generation ago: my parents-in-law (as did my own parents) first met on their wedding day. Today, young people may be able to choose the kind of ceremony they want. Last winter, my wife's brother and his then fiancee eschewed the traditional three-day feast and opted for a simplified Vedic version.

Not everyone has so much freedom. Once you give in to the idea of an arranged marriage - and 90 per cent of all Indian unions are arranged - you become a mere pawn in a greater game. Issues such as family status and Dad's business interests may overshadow the feelings of the principal cast. As for the event itself, it is a showcase for family prestige, rather than a romantic opportunity for two young people to formalise their love. Any slips in the festivities will be noticed and will fuel gossip for weeks. As a consequence, Indian families always opt for a prohibitively expensive extravaganza, rather than a subtly elegant, quiet affair; and few Indians marry within their means. Indeed, families start saving on the day their daughter is born. Pension funds routinely advertise investment schemes built around the idea of a daughter's wedding. Employees' perks include advances on gratuity and low-interest loans; jewellers offer monthly savings schemes.

High on the agenda, and almost as crucial as the right match, is the venue. Suitable places that can hold hundreds, sometimes thousands, of guests are in short supply in our overpopulated cities - and in a wedding-crazed city like Delhi, or a growing metropolis such as Bangalore, I have known families that have booked the venue before finding a groom.

The venue, the menu, the guest list and the trousseau are the high points of the decision-making. There are now special designer boutiques, and Delhi regularly hosts bridalwear fashion shows whose items can run into several thousand pounds. These pageants showcase India's top designers and their bridal lines - with names like Innocence, Frivolity and Solemnity.

Designer extravagance is, however, for the trendy elite or the nouveau riche. Most people go into the bursting bazaars of the inner cities - Old Delhi, for instance - to shop for the trousseau. My mother went direct to the weavers in their village homes to negotiate prices and pieces for my sister's trousseau.

Tradition may claim that it is the bride's family that suffers the agony, the tension and the expense of a wedding event, but that is not strictly true. The baraat, the groom's ceremonial procession, is the symbol of that family's honour, or izzat. While the bride's family will play host, it is the groom's father and his friends and relatives who bear the burden - fiscally and physically, of transporting the core group of the groom's party to the venue. Many weddings involve inter-city travel, and the logistics of such an effort can be awesome. For my brother-in-law's baraat, I travelled to Jaipur twice in the weeks preceding the wedding, to make sure that all arrangements for board and lodging were in order. On D-day, I drove ahead of the main coach, keeping in constant contact by mobile phone to make sure there were no upsets. But even so, allocation of rooms at the hotel went awry - and one aunt with rheumatism found all the ground floor rooms taken.

Given their investment in the proceedings, the groom's party thinks it is justified in throwing its weight around. An uncle of mine, a leading light of my brother-in-law's baraat and a man normally polite to the core, refused my offers to walk across the road to get his suit ironed at the nearest launderette, because he was so intent on persuading the bride's family to have an ironer posted on the premises. He wasn't fussing or being rude, merely following tradition and registering his attendance.

The arrival of the groom's baraat launches the wedding ritual - and a full wedding can stretch to three days. The enduring image of the baraat is the one where the groom arrives, dressed in the traditional tunic and loose trousers, astride a white horse, amid the cheers of the band that leads it and with dancing friends and relatives following. The bonhomie everyone displays is made all the greater by trips to the clandestine bar that travels with the baraat.

Westernised Indians will probably have a cocktail bar up and running at the venue - but in the average baraat, the boozing (preferably of whisky) is always men only and notionally secret, restricted to a tent or room on the fringes of the wedding venue proper. The ritual of drinking is as crucial as the hooch itself, and the secrecy of the act and the venue are maintained in mock seriousness by all men. This little enclosure is perhaps the only venue where both wedding parties drop their guard with each other.

Once the groom has arrived, the first stop is the mandap, the canopied area designated for the sacred fire. Small and well-contained, the fire is witness to the union and is central to a number of other rituals. These would normally include a set of vows and offerings of rice grains, thrown into the fire for wealth, health and happiness.

But first, the bride must be escorted to the altar and then "given away". This is the kanya dhanam, or donating the girl. It is a cathartic moment for the bride's family, representing as it does, in a purely literal translation of the hymns, the termination of the bride's relationship with her birth family. It inevitably moves whole families to tears.

Once the bride has been given away and the fire rituals completed, the bride and groom begin the ritual of the seven rounds of the fire, the saptapadi, which is followed by the groom applying red vermilion dye to the bride's forehead. This mark, the sindoor, is a symbol that a conventional woman will wear all her wedded life.

The rituals are not always gender-sensitive, but they do reveal and indeed strengthen the sense of community and extended family that still binds clans in India. This cementing of connections and relations distinguishes the arranged marriage from the love match - and will ensure that arranged marriages will survive, even when the marriage itself doesn't.

According to the latest surveys, marriages in India are breaking up as never before: the official Indian divorce rate of only 8 per cent overlooks the fact that in small towns and villages, the vast majority of married couples dissolve their marriages unofficially, rather than go through the humiliation of divorce. The figures have commentators and pundits publicly worrying about the state of the nation and the future of tradition. They have also inspired one enterprising southern Indian broadcasting company, Surya TV, to produce Divorce Reverse, a show for couples about to divorce. Husband and wife are seen spitting in the studio, heard shouting at one another. Then the host, a guest, and even the audience, provide free counselling.

The producers of Divorce Reverse claim to have averted many splits - though some suspect they will be turning their winning television formula into a Bollywood sequel: Monsoon Divorce.