Buying international air tickets in India

From my experience, for the round trips starts from India, travel agents in India gives very good deals when comparing the deals you get from the local travel agents in USA.

Consider these major facts

• Which agent gives you the best deal
• Service after buying the tickets, Ex., you need to place a service request for wheel chair, how do they help you out. 
• How fast they keep you updated, Ex., Flight / air line cancels their flight,  how soon your agent will inform you about this and help you getting your tickets booked in other airlines Or in case of bad weather if the flight gets delayed.
• Make sure you ask such questions before paying the money.

By registering in sulekha.com, you would receive calls from at least 5 to 6 travel agents(remember, if your parents can not do the online registering in sulekha, you can do that by giving their phone number, so they receive the calls).
Check  with your friends if they can refer someone to you.
Another option is, check with your company's travel desk whether they can do this if you pay for them, one of my friend who works for an MNC did this way, it is lot easier than approaching other agents.