How do you get a kelecleon in red rescue team if rob one?

You can't get a Kecleon in Pokémon Red Rescue Team.

While Kecleon is a Pokémon known for its camouflage ability, it was not introduced until the third generation of Pokémon games (Ruby, Sapphire, and Emerald). Red Rescue Team was released for the Game Boy Advance, which came before these games.

Therefore, Kecleon is not present in the game's Pokédex and cannot be obtained.