Airtel PR just sent me an email note saying that Airtel would be selling the iPhone 3GS in India in the coming months (no exact dates yet).
Bharti Airtel and Apple to Bring iPhone 3GS to India
[*] That page is still not live on the Airtel website.New Delhi, March 19, 2010: Bharti Airtel and Apple have reached an agreement to bring iPhone 3GS, the fastest most powerful iPhone yet, to India in the coming months. For information please visit www.airtel.in/iphone3gs*. For more information on iPhone, please visit www.apple.com/iphone.