In Hearthome City.
In Pokemon platnium it is wake gym leader. P.S. he has water type Pokemon.
beat snowpoint gym
you continue on to the next gym
luxary
By searching.
in pearl u beat hearthomes gym so its probally the same in platnium
You have you beat the gym leader first
you get it when you beat the 8th gym and go talk to the girl by the road to elite 4
go to Jubilife Poketch building after u get a certain number of gym badges. I think. lol :)
from veilstone city keep going down until you reach the beach then go left and you will see a path
go south of fantinas city then go east here is a tip crusher wake is that gym leader he uses water type my suggestion use an electric type those kind of attacks are super effective with water types Pokemon expert torie
You can't find Registeel in Pokemon Platnium. You just migrate it in Pokemon Ruby, Pokemon Sapphire, and Pokemon Emerald.