can plz tell whats area code for INDIAN IPHONES

I am using IPHONE 4 & Iphone 4S. issue with imessage. whnevr i try to send thru my immesage its hows my apple Id instead of my number.

I have tried all the discussions on apple support communities but it not worked for me. there is no option like caller id in imessage how can i change this if no option is there.

can anybody plz help me, its really bugging me....