HI whether you want to use iphone on t-mobile then you must first check that whether the iphone is locked or unlocked one ..If the iphone is unlocked one then you can freely use it with t-mobile sim ..Else if the iphone is locked with some other network provider then until you unlock it you can't use it with t-mobile sim ..You can easily unlock your iphone with the help of sites like Theunlockspot.com here they are rendering remote unlocking service to unlock all model iphone ....
