If i buy I pad air 2 in US, will it work with cellular network in India?

Good Questions Yugs

And that depends because as you may know there's 2 versions of the iPad Air 2

Wifi and Wifi+cellular

If you bought it contract free online from the apple store or on an actual apple store is unlocked already, if you bought it from a carrier with a plan you may need to request your carrier to unlock it in order to take it overseas

check this link for more info

http://www.apple.com/ipad/compare/

Here's more info about the model compared to the carrier available in the area

http://www.apple.com/ipad/LTE/

If this doesn't answer your question then you can call apple support, provide your serial number and they will tell you if the device is locked or not

 Hope it helps!!