Treecko is a Grass-type Pokémon that was first introduced in Generation III (Pokémon Ruby, Sapphire, and Emerald), which came out after Red Rescue Team.
While you can't recruit Treecko specifically, you can recruit other Grass-type Pokémon like:
* Seedot: You can find him in the Forest of Hope, starting from the lower floors.
* Shroomish: You can find him in the Forest of Hope, starting from the lower floors.
* Sunkern: You can find him in the Forest of Hope, starting from the lower floors.
These Pokémon can be powerful allies and help you progress through the game.