Pokémon Black OR White (Version 1 only; Black 2 / White 2 are NOT supported). Optional (for other regions): FireRed : Unlocks Kanto. Emerald : Unlocks Hoenn. Platinum : Unlocks Sinnoh.
PokéMMO uses different ROMs to provide different regions and features. While FireRed and Emerald give you Kanto and Hoenn, is essential because: Pokémon Black OR White (Version 1 only; Black