The phones cellular radio would have to be compatible with the network you wanted to use it with, plus unlocked so that you can connect it to what ever network it's compatible with.

T-Mobile uses GSM 850/1900 and UMTS/WCDMA 1700/2100

A quick google search resulted in this:

Other cools specs the NEC 931N Slider features is the 1Seg TV tuner and GPS function. There is also Bluetooth Connectivity, Infrared Connectivity, WiFi connectivity, supports microSDHC cards and WCDMA and GSM networks.

It might work, but you'd have to check the frequency range the radio operates in. GSM is just a transmission standard and can operate on any radio frequency.