You can catch Ralts south of petalburg city. Ralts is a great Pokemon trust me and if you have diamond/pearl get an extra male ralts and evolve it into kirlia. Give the male kirlia to your diamond/pearl and use a dawn stone on it and it will evolve into Gallade
U find Ralts in the area to the east of petalburg[the grass part in which a girl will be standing].
you could catch it with a poke ball
Route 102 on Pokemon Sapphire.
you can catch ralts on route 102 on emerald sapphire and ruby, but they are rare
Ralts evolves into Kirlia at level 20.
You have to evole a ralts to get a kirlia. There are none wild. Ralts are on Route 102
Ralts can be caught on Route 209 in Platinum. Ralts evolves into Kirlia at Level 20 or catch a Kirlia on Route 212
get RALTS from ruby\sapphire then migrate it to the other game train it till it's a curlia and last train it more ti'll its a gardevoir
you catch ralts at route 203 and 204 and use a poke radar
at lv 20
you can get one in petalburg city
You have to go to jubilife city go to the patches of grass use your poke rader . You wont get ralts right away . you need patience to catch a ralts . you can only catch ralts until you get the national dex
kirlia, gardevoir and gallade. any more? ask
Route 34 when on the radio they say that there is a large number of ralts in that area