Okay. If the phone is/was on a contract, they will ask for the name of the person. If they are very strict in verifying the proper owner, they might ask for latest bill payment receipt, which they will not.
Usually- IMEI. Which country you are in- Pakistan. (Too many stolen phones in Pakistan). Just tell them that you're cousin sent it to you since he didn't need it anymore. You can Bullchit your way through!
It will take maximum 2 days for your phone to get unlocked through iTunes. You just plug it in and after a few minutes, you get the same message as I got ^^
It's not hard, don't worry man!
Could also try this;
http://www.officialiphoneunlock.co.uk/unlock-iphone/Meteor-Ireland/