iphone software server could not be contacted

i got my iphone from US which was under AT&T . But it was unlocked from that service only after completion of their contract and it was brought here to india.

before it was unlocked it was updated to latest OS may be with indian sim card as much as i remember. And now after it was unlocked when i am trying to

switch on the phone it is showing the symbolic message to connect to itunes. When i tried to connect to itunes each and every time it is showing only one message " iphone software update server could not be contacted". Can you please help me out what to do to resolve this and start using my iphone.