I only know where regirock and regice is sorry....
You know that forest where roserad is?
Go there until you see a cave and bring a garchomp(hippodown temple)
then a rock with regirocks colors are is there use garchomps crush and the rocks will be smashed.
Regice: Remember lucario? in the cave where the save machine is, regice stature is I think burn is the move for it, but yeah go to where the room is just before lucario and destroy that rock, Hope I helped... Sorry I cant find registeel......
Source:Experience in catching regirock, Heres the real answers.
hope it helped!