I'm pretty sure you can find it in the White Forest. It should be in there, if not you could probably get one from wi-fi trade.
Check on www.serebii.net, but it's spelled ralts not raltz
First, capture a Ralts from a Pokemon Swarm (or trade from someone else). It must be a male Ralts. Then, evolve it into a Kirlia. Then, use a dawn stone to get a Gallade.
You have to catch him in a weak forest. they're very weak.
You catch various Pokemon from 1st,2nd,3rd and 4th generation Pokemon games, eg happiny, ralts etc.
battle the elite 4(with a cheat) and capture will's Pokemon only with cheat though:{ get action replay,or migrate a ralts
Ralts is a swarming Pokemon at Route 34. You can also trade or transfer a Ralts from another game.
Ralts will evolve into Kirlia at level 20. It will then evolve into Gardevoir at level 30. If male, it can evolve into Gallade by exposing Kirlia with a Dawn Stone.
You will need to trade it from Pokemon White. Or you can get it at Spooky Manor in the Dream World (Over 10,000 dream points).
It is in White Forest when Lena is the resident of the forest. If not you'll need to use the Entralink to connect with Pokemon Black and visit that version's Black City.
In Pokemon White, N will capture Reshiram, and you will be able to capture Zekrom. This will happen vice-versa in Pokemon Black. This is one of the main differences between Pokemon Black and White.
Sadly, a relicanth is more rare than a ralts. And it takes FOREVER to capture a ralts. Anyways. Well, first, you probably should have pokemon lv. 30-40. Go to the place you can capture relicanth, and basically search for one. Unless you have an AR. I can't remember where you can get a relicanth, all I know is you have to use the HM dive to get there.
at lv 20 that is when ralts evolves