Jirachi is a mythical Pokémon and was only obtainable through special events in the past. It was never available through normal gameplay in any Pokémon game, including Emerald.
Here's why:
* Event Exclusivity: Mythical Pokémon are designed to be rare and special. They are typically distributed through events held at conventions, game stores, or other special occasions.
* Game Mechanics: The game code for Emerald does not contain any way to encounter or obtain Jirachi through standard gameplay.
* Game Shark and AR: These devices allow you to modify game data, including adding Pokémon to your game. However, this is considered cheating and goes against the spirit of playing the game.
Therefore, if you want to obtain Jirachi in Emerald, you would need to have acquired it through a past event, or use a cheat device like Game Shark or AR.