India, eh? Whereabouts? I'm going there this summer to teach in mumbai and new delhi.
Do you live there, or just visiting?
Anyway, I'm pretty sure the atrix is locked (which means carrier locked, or locked to a certain carrier, like at&t in this case). But don't despair, because "unlocking" your phone is not a difficult task. The easiest way is to call at&t and ask for an unlock code, because you're going to be in india and need your cell phone to work with another carrier. But if at&t won't give it to you (they can be jerks sometimes!) then just sit tight; the XDA crew will almost certainly create an unlocking guide, in time (assuming they haven't already).
There are also ways to pay websites money for an unlock code? But I have never done that and can't verify how well it works, if at all.