Ambani, who would later that year wed Radhika Merchant in a six-day traditional Indian wedding ceremony in Mumbai, showed off his luxury Richard Mille to Zuckerberg and his wife Priscilla Chan.

It all started in March with a three-day pre-wedding celebration in Mukesh Ambani’s hometown Jamnagar, in the western Indian state of Gujarat. Guests included Mark Zuckerberg, Bill Gates ...