It acts as a digital key that unlocks the encrypted game files.

If you own a legitimate digital copy of Tekken Tag Tournament 2 from the PlayStation Store, you can legally extract the RAP file from your PS3 console. This process requires a console running custom firmware (CFW) or PS3HEN:

If you want to move your purchased PSN games to another console or to the RPCS3 emulator, you can create installable PKG files along with their corresponding RAP licenses using tools like TrueAncestor or PS3 Disc Dumper.

Place the game_license.rap file in the root of a FAT32 USB drive. Insert the drive into your PS3.

While I couldn't find a direct link to a specific rap file, I did enjoy exploring the game's soundtrack and sound effects. The game's music is high-energy and complements the gameplay well. If you're a fan of electronic and action-packed soundtracks, you'll likely enjoy the music in Tekken Tag Tournament 2.