Lavish wedding celebrations for the son of Asia's richest man resumed on Saturday with a star-studded guest list including Hollywood celebrities, global business leaders and Indian Prime Minister Narendra Modi.

Billionaire tycoon Mukesh Ambani's youngest son Anant and his fiancee Radhika Merchant, both 29, are tying the knot over the weekend in Mumbai following months of pre-marriage parties that have set a new benchmark in matrimonial extravagance.

Saturday's itinerary included a blessing ceremony during which the world's rich and famous greeted the couple at the wedding venue, a 16,000-capacity convention centre owned by the Ambani family's conglomerate.

Footage from inside shared by local broadcasters showed Modi, whose policies have been warmly supported by the groom's father over his decade in power, was among the guests to pay their respects.

The event followed a formal ceremony and party on Friday attended by the likes of socialite Kim Kardashian, actor John Cena, and former British premiers Tony Blair and Boris Johnson.

FIFA boss Gianni Infantino, Bollywood superstar Shah Rukh Khan and Samsung chairman Jay Y Lee were among the hundreds of other famous figures present.

"Best wishes to the new couple and double happiness!" Chinese ambassador to India Xu Feihong posted on social media platform X along with footage of the couple from inside the venue.

This weekend's celebrations end on Sunday with a reception party, and cap months of extravagant pre-wedding festivities.

Earlier events this year included a party at the Ambanis' ancestral home where a purpose-built Hindu temple was unveiled, and private performances by R&B star Rihanna and Canada's Justin Bieber.

Guests at that gala included Facebook founder Mark Zuckerberg and former US president Donald Trump's daughter Ivanka, along with a who's who of India's sporting and entertainment worlds.

In June, the couple embarked on a four-day Mediterranean cruise along with 1,200 guests, with singer Katy Perry performing at a masquerade ball at a French chateau in Cannes.

Mumbai this year overtook Beijing to become the Asian city with the most billionaires, according to a Chinese research institute survey.

But despite India being the world's fastest growing economy, the gap between rich and poor remains vast. More than half of the country's 1.4 billion people live on less than four dollars per day, according to World Bank figures from 2021.

While the wedding and its VIP attendees have been the subject of relentless and laudatory media coverage in India, the reaction among the public has been mixed.

"They must have spent over US$60 million, while I will struggle to earn just US$400 this month," said Mumbai general store worker Jitesh Ingle.

"But this is our life. What can we do? We can only watch their celebrations on YouTube."

Anant's father Mukesh is chairman of Reliance Industries, a family-founded conglomerate that has grown into India's biggest company by market cap.

The patriarch is the world's 11th richest person with a fortune of more than US$123 billion, according to Forbes, and is no stranger to making a statement when it comes to family marriages.

He held the most expensive wedding in India to date for his daughter in 2018, which reportedly cost US$100 million and saw US singer Beyonce perform.

The family's lucrative interests include retail partnerships with Armani and other luxury brands, more than 40 percent of India's mobile phone market and an Indian Premier League cricket team.

His 27-floor family home Antilia is one of Mumbai's most prominent landmarks, reportedly costing more than US$1 billion to build and with a permanent staff of 600 servants.

Merchant is the daughter of well-known pharmaceutical moguls. (AFP)