That means that you will have to deal with a split. There must be a minimum of 2 players and a maximum of 4 for the heist to happen. The first thing to note is that this is not a solo heist. Like all the other heists in GTA Online, the Diamond Casino Heist has a lot of variations and different ways that it can go down. The Variations Of The Diamond Casino Heist There are many different approaches on how you can steal from the Diamond Casino in GTA Online.