To use emulators like RPCS3 legally, you should dump the files from your own physical copy of the game.
For a more official route, you can stream the game on PC if you have a PlayStation Plus Premium subscription. System Requirements for Emulation Tekken Tag Tournament 2 Pc Download Highly Compressed
Known for being highly optimized, Cemu can run the Wii U version of TTT2 smoothly on mid-range hardware. To use emulators like RPCS3 legally, you should