Won't work- this is not a GSM device

That's about it. You need a GSM based device for use on T-Mobile's network. Grab either an international version, or ATT's version of the S3 to at least get the ball rolling. Always check GSM arena (etc.) for the specs. Go here-

http://www.gsmarena.com/samsung_galaxy_s_iii_i535-4799.php