The game must be on your internal HDD (not running from the disc).
Given the context, it's very likely the "Red Motion" mod menu is a variation of the "Motions Mod Menu v3," which was released as a free mod menu for GTA IV on PS3. Users on modding forums have discussed how to install it, with questions about renaming files like script.img to update.img . It appears to have been a popular menu in its time, with users seeking help to install it on CFW and inquiring about its online functionalities. gta 4 red motion mod menu ps3