If anyone doubted the scale of Reliance Industries’ (RIL’s) ambition in re-entering the Indian telecoms market, those whispers were silenced at this week’s launch of Digital India Week. Reliance Jio Infocomm, the conglomerate’s youthful wireless operator subsidiary, shared top billing at the event with the largest Indian mobile carrier, Bharti Airtel. Huge sums were bandied around – $39.2bn by RIL, $15.7bn by Airtel, much of that earmarked for 4G. While the two companies’ CEOs were full of smiles on the day, Airtel has a challenge to respond to the launch of Reliance Jio’s 4G services this year, and to defend its lead in a market which has been suffering from over-competition and razor-thin margins for years, even without the entry…