Disclaimer: Playing unauthorized digital copies of games (ROMs/ISOs) may infringe on copyright laws. This article focuses on the technical functionality of PS3 PKG files. If you'd like, I can: Tell you which are safest. Rank the Tekken games available on PS3 by compatibility.
PKG repackaging of PS2 games
A small app that creates a "slot" for PS2 games to run. tekken 4 ps3 pkg work