Tekken 6 (and thus its mods) is demanding on the PSP hardware. On PPSSPP, tweak these settings for a stable 60 FPS:
: 2x PSP (Budget devices) or 3x/4x PSP (High-end phones and PC). Tekken Tag Tournament 2 Ppsspp Isoroms
Some fan-made mods for Tekken 6 on PPSSPP add tag mechanics, dual lifebars, and custom character skins. Search for (not TTT2). These mods are clunky and unstable, but they exist for the curious. Tekken 6 (and thus its mods) is demanding