By Devidutta Tripathy NEW DELHI (Reuters) – If he bets big, billionaire Mukesh Ambani will emerge from this weeks Indian airwave auction armed with spectrum that could make his Reliance Industries Ltd a formidable rival to market leaders Bharti Airtel Ltd and Vodafone Group PLC. Even if he bids modestly, Asias second-richest man can walk away with airwaves that would allow his Reliance Jio to compete in the cut-throat Indian market for basic phone services. Shares in Indias biggest cellular carriers lost between 4-7 percent in a single day after Reliance threw its hat in the ring for this weeks auction and have yet to recover. With Reliance Jio entering, the competition again hots up. India is auctioning airwaves in both the 1800 megahertz and 900 megahertz bands, and Reliance has unexpectedly opted to compete for both, sources have said.