a friend of mine has a 91 mk3 supra with a 2jz twin turbo and a six speed trans apparently the car came stock that way is that possible?
No. The 2JZ wasn't introduced until the 1993 model year and in the MkIV Supra, same-same the 6-speed transmission (Getrag V160 I think). Someone swapped them in at some point from a donor MkIV.