Q: my brother want to buy i pad air for me from usa ...but it will use in india ..so please suggest me which network i pad he buy for me in usa ..

There is no need to get a US Carrier if the Device is going to be used outside the US.

you can use a nano-SIM card from a local carrier

iPad Air with Wi-Fi + Cellular can roam worldwide on GSM/UMTS networks. In countries without compatible LTE networks, iPad Air will operate on GSM network technologies such as HSPA+ and DC-HSDPA. When you travel internationally, you can use a nano-SIM card from a local carrier.

From Here >  http://store.apple.com/us/buy-ipad/ipad-air

Try India here >  http://support.apple.com/kb/ht1937 for Carriers...