HI yes if it is unlocked then you can sure use it with 3 network sim .Else if your Motorola RAZR v3 mobile is locked to some other network provider then until you unlock it you can't freely use it with any GSM sim .You can easily unlock your phone using sites like ProUnlocking.com they are providing unlock code for all mobile models at reliable cost .You first check that whether the code is available for your country and network provider .If yes then pay for it and unlock your phone .