Can I unlock my sprint iPhone 4S for use on tmobile?

I have a sprint locked iPhone 4S and I want to get it unlocked or something to make it able to work with my tmobile SIM card with my tmobile plan

No they are two different networks sprint is CDMA & T-Mobile is HSPA+ so they are not compatible. However you can put sprint on Verizon and virgin/boost mobile & metropcs.