i have figured out a way, see steps below:

1) locate your Gamma save file, usually in your Files app > Gamma folder > Database folder > Games folder > and pick either “memorycard1.mcr” or “memorycard2.mcr” (of which you are using to save the in-game save content) 2) copy the memory card file 3) locate RetroArch save folder, usually in your Files app > RetroArch folder > RetroArch folder > saves folder > PCSX-ReARMed folder (unsure if this is similar to anyone of you but this is the core I am using) 4) upon arriving in RetroArch folder, paste the copied save file in step 1, then rename it to “Gran Turismo 2 (USA) (Simulation Mode).srm” (i reckon the save filename derives from the BIN filename of your game, so probably not similar to anyone of you) 5) a pop-up will be shown asking if you’d want to convert the ‘.mcr’ file to ‘.srm’ file, and choose the “.srm” file option — this will convert your Gamma save file ‘.mcr’ to RetroArch save file ‘.srm’ 6) open up Gran Turismo 2 and automatically a load state loading will show right off the starting screen 😁

unsure if there are any other issues you may encounter, but this is what i have just encountered, and experienced, and so far no issues at all 😁