If you mean how many Pokemon he will have when battling alongside with you, two.
If you mean a list of all the Pokemon Hilbert has a possibility to bring out, they are:
Offensive Pokemon
- Conkeldurr
- Excadrill
- Mienshao
- Sawk
- Krookodile
- Darmanitan
- Archeops
- Reuniclus
- Vanilluxe
- Escavalier
- Eelektross
- Chandelure
- Haxorus
- Accelgor
- Beartic
- Cryagonal
- Druddigon
- Golurk
- Bisharp
- Bouffalant
- Braviary
Defensive Pokemon
- Musharna
- Gigalith
- Throh
- Audino
- Lilligant
- Conkeldurr
- Cofagrius
- Scrafty
- Gothitelle
- Reuniclus
- Amoonguss
- Vanilluxe
- Ferrothorn
- Jellicent
- Klinkklang
- Chandelure
- Durant
- Accelgor
- Mienshao
- Mandibuzz
- Eelektross
- Alomomola
If you want a list of full movesets for each Pokemon, visit Bulbapedia.
