If your T-Mobile phone is an optimus f6 then yes you can.
TY.
Edit: I was using Xperion ROM (4.1.2) with SD hack. Backup data from SD to computer. Then, I repartitioned my SD using Minitool Partition Wizard for more space on the FAT32 partition. (deleted old partitions, reformat using SD formatter, then remade partitions):
Partition 1 = FAT 32 Primary (~8/32 GB/GB)
Partition 2 = ext4 Primary (~24/32 GB/GB)
Easy steps for upgrade success (camera works for me):
1) Backup data on SD to computer* & transfer ROM install zips to SD
2) do a full wipe of phone using TWRP & reboot to TWRP (agree to TWRP install SuperSU)
3) insert SD into phone, mount, install ROM & gapp zips, reboot into system
4) let ROM load and setup (install & update important user apps)
5) reboot into TWRP
6) wipe cache, dalvik, install latest
kernel with gsm fix
7) reboot into system, finish loading, then reboot into TWRP
8) install SD hack (init.d version)