Mukesh Ambani, chairman of Reliance Industries

Mukesh Ambani, chairman of Reliance Industries

Pankaj Nangia/Bloomberg

Amid scant funding from the government, which is struggling to contain the widest budget deficit among major emerging economies, billionaires Lakshmi Mittal and Mukesh Ambani, pictured, have stepped in to bankroll training and equipment for athletes and try to put more Indians on the podium in London.