With a networth of USD18.6 billion, Reliance Industries Ltd (RIL) chief Mukesh Ambani leads the pack of 56 billionaires based in India featured on the list.Mukesh Dhirubhai Ambani was born on 19 April 1957 is an Indian business magnate who is the Chairman, Managing Director and largest shareholder of Reliance Industries Limited (RIL), a Fortune Global 500 company and India's second most valuable company by market value.Claimed to be the most expensive house in the world, Antilla is a 27 story, 40,000 sq ft tower standing tall at a height of about 570 feet above the ground level with an approximate interior space of about 400,000 sq ft.