The PhilePatcher does NOT work with this mod due to the patches creating larger ISOs. You need to use the program Delta Patcher to apply any patch of Deep Cuts to default TimeSplitters 2.

Download Delta Patcher here: https://www.romhacking.net/utilities/704/

To install a patch, select an unmodified TimeSplitters 2 NTSC-U GameCube ISO and one of the three Deep Cuts patches. Apply that patch to the ISO using Delta Patcher. Make sure to create a backup copy of the ISO beforehand.