The Grand Theft Auto Double Pack contains two versions of the Grand Theft Auto video games; Grand Theft Auto 3 and Grand Theft Auto: Vice City.
Cheats for Grand Theft Auto Double Pack are identical to the cheats for the original games that are included in the double pack.
So if you are playing GTA3 (from the double pack) you would simply use the GTA3 Cheats. If you are playing Vice City from the double pack then you would use cheats for Grand Theft Auto: Vice City.
Here are the cheats for the two versions of GTA included in the game pack: