Carriers: Two U.S. carriers currently serve India: Northwest (partner of KLM from Holland) and Delta Airlines. Both fly regularly to Mumbai and Delhi. You can find Northwest/KLM at http://www.nwa.com/ You can find Delta at http://www.delta.com/ Many non-U.S. carriers also serve India. These include Air India, British Airways, Air France, El Al, Kuwaiti Airways, and Gulf Air.
The best price for tickets on either U.S. or non-U.S. carriers are often found from consolidators, who buy tickets wholesale, or specialty travel agents who specifically serve India. These travel agents are often able to make additional travel arrangements, such as air and rail travel within India.