DANCE
by defeating all the gym leaders and the elite four
You can only catch it after beating the elite four however you can get it from a friend before defeating the elite four.
After defeating the elite four you can get it in Sky Pillar along route 131
In Pokemon Ruby and Sapphire Rayquaza can be found at the top of the Sky Pillar on Route 131 after defeating the Elite Four and the Champion. In Pokemon Emerald you can enter and catch Rayquaza before defeating the Elite Four during a story event.
The elite four will be at the Pokemon league.
Celebrate.
The Pokemon League
unusual u will get legendary Pokemon
6 deoxys level 100
yes swarpert is a greatest Pokemon to defeat elite four
You cannot capture Latias before defeating the Elite Four and the Champion. You will need to use the GameShark to do this. If you are playing Pokemon Ruby, then an Eon Ticket is required to capture her on Southern Island.
you can't catch him in Pokemon hoenn region but!! you can trade him from Pokemon firered and leafgreen with a link cable, yet in Pokemon emerald you can catch him in the repaired safari zone after defeating the elite four