Iphone unlocking and Apple iOS clarifications

Are you thinking of buying a smartphone while staying abroad in countries like Oman? Do you want to know whether you can use a smartphone in Muscat when you buy it from Oman and also use the same when you come to India? Follow this thread to read answers by experts to these and other related questions regarding buying of a smartphone in one country and using the same in another country.

I am planning to buy an iPnone 4 from Oman. I want to use this phone both in India as well as Oman. Can I use this phone directly here in Muscat and also in India?