I'm planning to buy ipad mini 2 in USA ( no contract) and use it in India, if something goes wrong will india service center help me in resolving the issue and the warranty is global or region based?

Since you mention no contract, are you referring to one that is wi-fi and cellular capable? Otherwise it wouldn't matter.

Unless you buy a Wi-Fi + Cellular iPad, I don't see a problem.

Warranty is NOT International, so any warranty or services iPad must be brought back to U.S.

If you have any problems with it you are likely to have to return it to the US for service, as ckuan says above, you won't have an international warranty.