From Bulbapedia, the community-driven Pokémon encyclopedia.
In the Battle Maison challenges, the player will face Trainers that typically use Pokémon randomly selected from a roster specific to the Trainer. Every roster will only contain Pokémon from the following lists. Each listed species will have four predetermined combinations of item, moves, nature and effort values. Gender and ability are randomly determined, and individual values are determined based on the Trainer.
Lists of normal Battle Maison Pokémon by region
Lists of Super Battle Maison Pokémon by region