By Zoya Mateen & Meryl Sebastian, BBC News in Delhi and Kochi
Reality TV star Kim Kardashian and former UK Prime Minister Tony Blair are among the international guests in Mumbai for the wedding of Asia's richest man's son.
Anand Ambani, son of Reliance Industries chairman Mukesh Ambani, is set to marry Radhika Merchant, daughter of pharma tycoons Viren and Shaila Merchant.
The four-day wedding extravaganza in the city of Mumbai was the final stop of the lavish parties the family had hosted since March.
The city's main roads will be closed for several hours a day until the festivities end on Monday.
Months of extravagant celebrations have already featured performances by popstars like Rihanna and Justin Bieber.
But it has led to a backlash — city residents have complained about traffic jams, while others have questioned the lavish display of wealth at endless celebrations.
On Friday, parts of the city were lashed by heavy rains and floods.
66-year-old Mukesh Ambani is currently the 10th richest man in the world with a net worth of $115 billion, according to Forbes. Reliance Industries, founded by his father in 1966, is a conglomerate that operates in sectors ranging from petroleum and retail, to financial services and telecommunications.
Anant Ambani is the youngest of his three children, all of whom are members of the Reliance Industries Group. The 29-year-old is involved in Reliance's energy businesses and is on the board of Reliance Trust.
On Friday, the couple will tie the knot in a traditional Hindu ceremony at the Jio World Convention Center.
Reports say the family will host a grand reception over the weekend, ahead of a final reception for their housemates on Monday.
Rumors on the internet suggest that Adele might star in the wedding, but the family has not confirmed this.
Pictures and videos of Kim Kardashian out on the town with her sister Khloé Kardashian are widely shared online.
Reports say that the sisters brought in a team of stylists, including celebrity hairstylist Chris Appleton, along with a team of producers to capture every detail of their trip.
Former Indian President Ram Nath Kovind, British High Commissioner to India Lindy Cameron and US Ambassador to India Eric Garcetti have also arrived in the city to attend the wedding.
Mumbai police have labeled the wedding, which will be attended by many international and Indian VIPs, a « public event », Reuters news agency reported.
The city police have also imposed traffic restrictions around the festival venue.
From Friday to Monday, roads around the convention center will be open only for « event vehicles » till midnight 13:00 India time (07:30 GMT), it said.
Rajan Mehra, CEO of air charter company Club One Air, told Reuters the family had chartered three Falcon-2000 jets to transport wedding guests to the event.
« Guests come from all over and each flight makes multiple trips across the country, » he said.
The restrictions have sparked anger among city residents, who say they are already struggling with traffic jams and rain floods.
The wedding festivities began in March, with the family celebrating three days before the wedding in their home state of Gujarat.
Among the 1,200 guests who attended the celebration were international celebrities, politicians and members of the business world – including Meta's Mark Zuckerberg and Microsoft's Bill Gates.
The party kicked off with a performance by Rihanna on the first night. Diljit Dosanjh, the first Punjabi singer to perform at Coachella, took the stage on the second night, while rapper Akon closed the show on the final day of the festivities.
In June, the Ambanis organized another pre-wedding celebration, this time with a luxury trip from Italy to France. Backstreet Boys, Katy Perry and Pitbull performed for 800 guests that included Bollywood stars and cricketers.
And then the final round of celebrations began when Bieber landed in Mumbai earlier this week.
Social media has been flooded with photos and videos of her singing in front of ecstatic audiences.
Money was lavished on the construction of 14 temples within a sprawling complex in Jamnagar to showcase India's cultural heritage and provide a backdrop for the wedding. As part of the celebrations, the Ambanis also conducted mass weddings for 50 destitute couples.
On Wednesday, the family hosted a bandara — a community feast for the downtrodden.
The Ambanis have not disclosed how much the wedding will cost, but wedding planners estimate they have already spent between 11 billion and 13 billion rupees. [$132m-$156m]. Rihanna was rumored to have received $7m (£5.5m) for her performance, while Bieber was tipped for $10m.