Root Need help with odin.....

[malice777]

Hey guys so i soft bricked my s6 and am having trouble flashing stock firmware. i bricked it trying to flash TWRP and after that it got stuck in a bootloop. i cant boot into recovery mode bcuz i think i screwed up the recovery partition flashing it. however i can boot into download mode and use odin but i always get "operation fail" in the end. my device is an sm-g920i with no supported firmware thru samsung mobile or my carrier, but i spoke with a technician and he said that its possible to flash a tmobile version of firmware on my phone itll work but i still get "operation failed.........i need help