India is still recovering from two back-to-back celebrity weddings but it's already time for the next one. This time it's the children of two Indian billionaires, who are all set for what promises to be the next level of big fat Indian weddings.

Isha Ambani, the daughter of India's richest man, Mukesh Ambani, will marry Anand Piramal, the son of another billionaire industrialist on 12 December. Celebrations kick off this weekend in Udaipur, a royal city that is now a coveted wedding destination.

The last time a wedding of an Indian businessman's family got this much attention was in 2004.

Indian-born but London-based steel tycoon Lakshmi Mittal hosted his daughter's wedding at France's historic Palace of Versailles and a grand chateau. The bill, which included gifts for family friends, ran up to $55m at the time.

The wedding ceremony of Ms Ambani and Mr Piramal is not quite on that scale, but "leaked" details are still greatly exciting Indians - and it caps a year of Instagram-fuelled celebrity wedding fever.

The platform's Indian universe is as driven by celebrities and influencers as anywhere else, but weddings provide it with its fashion oxygen.

Indian fashion - and increasingly photography - on the platform is dominated by brides, grooms and their parties.

And 2018, which has been a year quite unlike any other in terms of wedding bashes, will be capped off by the Ambani-Piramal wedding.

Celebrity bloggers, entertainment writers and lifestyle magazines have been scouring Instagram to keep up with the pre-wedding festivities, which will stretch over at least three days.

The wedding invites - sent in fancy mini-chests with gifts tucked inside - have their own share of Instagram videos.

The families have kept most details under wraps but rumours are rife.

India's biggest national newspaper has claimed that Beyoncé will perform at the sangeet, an evening of music and dance that typically precedes the wedding. The tradition originally involved friends and family putting on impromptu performances at intimate gatherings - but now it's far more common to see a few hours worth of choreographed dances as the latest Bollywood songs are belted out.

Several Bollywood stars themselves are expected to perform at Ms Ambani's sangeet, according to local media reports. Actors are sometimes hired to perform at sangeets or other private events by those who can afford it.

But many of Bollywood's biggest stars are personal friends of the Ambanis and are often seen attending parties hosted by the family.

The Ambanis themselves attended the recent wedding reception of Bollywood actors Deepika Padukone and Ranveer Singh; and Isha Ambani was a bridesmaid at the wedding of actress Priyanka Chopra, which took place in Jodhpur, also in Rajasthan state, last weekend.

Udaipur, the location for the Ambani-Piramal wedding - is a 16th Century city. Studded with lakes, it is home to some of India's most luxurious hotels, including a 272-year-old marble-walled palace in the middle of a lake that now serves as a hotel. It's a small city with a mostly quiet airport, but it will be busy this weekend - the families of the bride and groom have reportedly chartered at least 30 flights to fly guests in and out.

This latest wedding comes on the heels of other plush, glamorous ones.

The photos of Chopra and US singer Nick Jonas's wedding were carefully released on Instagram over a period of days, producing both envious gasps and eye-rolls for the extravagance on display. Her 75ft long tulle veil made international headlines and videos of her sangeet, which resembled an awards ceremony, went viral.

Padukone and Singh's wedding was a far more intimate affair at a resort on Italy's Lake Como (where Ms Ambani and Mr Piramal got engaged) but it was followed by four different receptions in India. And Padukone's outfits ranged from traditional (intricate hand-woven saris) to seductive (a sparkly red couture gown by Lebanese designer Zuhair Morad) to dramatic (a floral concoction that Singh said made her look like "Frida Kahlo on acid").

And the couple's outfits were co-ordinated - if they didn't match colours, which they often did, they opted for starkly different ones.

Bollywood star Sonam Kapoor's wedding to businessman Anand Ahuja in May was also almost exclusively documented on Instagram. Sonam, who is considered a fashion icon, sometimes switched outfits multiple times in a single evening - and her sartorial sense became a popular topic.

Those who attended her star-studded reception also uploaded candid videos of actors and celebrities dancing with one another and singing (very badly), which quickly went viral.

Over the last year, Instagram has redefined the way Indians get information about celebrity weddings.

It's where photos are first released and where much of the media also gets news of what has occurred behind closed doors.

And on the celebrities' side, posting to Instagram is a carefully co-ordinated affair.

As Priyanka Chopra and Nick Jonas, Deepika Padukone and Ranveer Singh and even Indian cricket captain Virat Kohli and Bollywood star Anushka Sharma showed, the done thing is to upload the exact same, carefully filtered couple photograph onto each person's Instagram feed at the same time.

Padukone and Singh upped the ante a little by also only posting pictures of each other on their feeds.

And with the pressure on to post beautiful pictures, everyone seems willing to go that extra mile - with emphasis on extra.

"The biggest victim of the Instagram show-off is Bollywood," says Shefalee Vasudev, who edits digital magazine The Voice of Fashion. The social media curation exhibits the "latent competition at play among the privileged, and especially among Bollywood stars", she says.

That may be so, but Indians are not exactly complaining.