The 3 Regis
First you must have a Wailord, Relicanth and a pokemon that knows dig. Go to Pacifidlog and surf to the currents find a place to dive in and dive go down and put relicanth in front of your Pokemon and Wailord at the last read. read the braille and dive up. Read the farthes braille on the wall in the miiddle then use dig. It will say that you will go under water but its not. It will open the sealed chamber when you in the chamber, switch relicanth with Wailord and read the farthest braille in the middle. There will be an earthquake. (you can now deposit relicanth and wailord)
Go to lilycove. Go to the big rock where there is a ruin maniac. The rock now has an entrance. go in. Read the braille in the middle then use flash in the middle of the cave and the braille will crack open go inside and registeel will be there.
Go to dewford surf up until you found the big rock. Go in. read the braille then run clockwise in the cave. you sould be always at the edge(you cannot walk or use a bike). Once you reach the braille click the middle the braille will crack open and regiice will be there.
Go to the desert and find the big rock. go in and read the braille in the middle. move left, left and down,down and use rock smash the braille will crack open. go in and regirock will be there.