Here's why you can't catch Rayquaza in Pokemon Ruby:
* Different Regional Pokemons: Each Pokemon game has different regional Pokemon available. Ruby, Sapphire, and Emerald each have their own unique set of Pokemon.
* Rayquaza's Role: Rayquaza is a key part of the story in Pokemon Emerald. It's involved in the climax of the game and is not found in the earlier games.
If you're looking to catch Rayquaza, you'll need to play Pokemon Emerald.
Here are some tips for catching Rayquaza in Emerald:
* Prepare for a tough battle: Rayquaza is a powerful Pokemon, so be sure to bring your best team with you.
* Use a Master Ball: The Master Ball is guaranteed to catch any Pokemon.
* Utilize status conditions: Status conditions like paralysis or sleep can help you catch Rayquaza more easily.
* Lower its HP: The lower Rayquaza's health, the easier it will be to catch.
* Use Ultra Balls or Timer Balls: These Pokeballs have a higher catch rate.
Good luck catching Rayquaza!