Red's Pokemon from Pokemon Origins

 

A list of the following Pokémon in Red's party as shown in "Pokémon Origins".
*Charmander (fire)/Charmeleon (fire)/Charizard (fire/flying)/Mega Charizard X (fire/dragon)
*Rattata (normal)
*Spearow (normal/flying)
*Caterpie (bug)/Metapod (bug)
*Pidgey (normal/flying)
*Nidoran (male) (poison)
*Magikarp (water)
*Jolteon (electric)
*Snorlax (normal)
*Psyduck (water)
*Lapras (water/ice)
*Haunter (ghost/poison)/Gengar (ghost/poison)
*Victreebel (grass/poison)
*Kabutops (rock/water)
*Hitmonlee (fighting)
*Scyther (bug/flying)
*Dodrio (normal/flying)
*Persian (normal)
*Fearow (normal/flying)
*Arbok (poison) (kept in Great Ball)
*Tentacool (water/poison)
*Pikachu (electric)
*Chansey (normal) (kept in Safari Ball)
*Rapidash (fire)
*Tauros (normal)
*Articuno (ice/flying) (kept in Ultra Ball)
*Zapdos (electric/flying) (kept in Ultra Ball)
*Moltres (fire/flying) (kept in Ultra Ball)
*Mewtwo (psychic) (kept in Ultra Ball)

According to his page, Red has 150 Pokémon in his collection; including one of each Pokémon featured in Generation I (minus Mew), he caught several Pokémon off-screen.

Pokémon (c) Nintendo, Game Freak