First, you've got to go to the cave. If you know about 'the seal', then I assume you know where the cave is.
You've got to go the the cave with a Wailord at the back of your party and a Relicanth at the front. If that doesn't work, then put the Relicanth at the back and the Wailord at the front.
Go to the Morse Code at the end of the tunnel and examine it. After doing that, get any Pokemon to use Dig. Instead of escaping, they will be this big BANG!
Then you can catch the Regis in 3 different caves.
You can only get regi ice in sapphire,ruby,and emerald.
3 ^ight thx
migrate it from ruby, sapphire, or emerald
throw a lot of ultra balls
ok you kinda need to trade them from ruby or Sapphire after receiving the rubi and Sapphire in Pokemon fitrered!
you have to import it from emerald,ruby or Sapphire you have to import it from emerald,ruby or Sapphire
You can look on youtube.com and type in how to get the regis and there is a complete walkthrough on how to get there.
All of the Regi's are on level 40 when you encounter them.
DotBraille is Regi's language in Ruby, Sapphire and Emerald. By reading them in the walls and de-coding them, you can find Regi's (expect Regigas!).
The regi's didn't exist in Generation 2 games. They were introduced in generation 3, namely ruby, sapphire, and emerald.
Sorry but you can't get them on Pokemon Platinum. You have to migrate regi rock regi steel and regi ice from eiter ruby or sapphire, ( idk about emerald) i hope i helped ;)
watch "how to get the three regi's" on youtube