Capturing a Regirock is quite a feat; it's hard to find, and you won't be able to do it until you've beaten the league and unlocked the Clay Tunnel. Once you have met these prerequisites and collected the necessary items (listed in the "Things You Will Need" section), you are ready to begin your hunt!
Steps
Method 1 of 4: Enter the Clay Tunnel
Step 1. Make sure you have all the items listed in the Things You Will Need section
Otherwise you won't be able to catch Regirock.
Step 2. Find the Clay Tunnel
The Tunnel is a long, cave-like tunnel located northwest of Libecciopolli. We remind you again that you will only be able to access the tunnel after beating the Pokemon league.
Step 3. Enter the Clay Tunnel
You will need a Pokemon that knows Surf.
Method 2 of 4: Inside the Clay Tunnel
Step 1. Proceed north after entering the tunnel and then east to the first fork
Talk to the character you see. You will enter a new section of the Tunnel.
Step 2. Proceed south to the end of the tracks
Then go west, and then north.
Step 3. Keep going north until you meet another character
Talk to him to enter the next section.
Step 4. Proceed south, then east to the corner, and talk to the next character to continue
Then, continue south and talk to the next character.
Step 5. Proceed to the blue pond
Use your Pokemon with Surf to swim to the door, and talk to the character. The door will open; go north and enter. You will enter the Underground Ruins.
Method 3 of 4: Inside the Underground Ruins
Step 1. Go north to the great door, but don't enter
Stand in the center of the circle on the ground, and then walk six steps south and nine steps east.
Step 2. Turn south, but don't take another step
You should find a secret switch that will open the door.
Step 3. Enter the door
You will reach Regirock's chamber.
Method 4 of 4: Inside the Regirock Chamber
Step 1. Save the game
So, if you lose the fight or defeat Regirock before he's captured, you can repeat the battle.
Step 2. Talk to Regirock
A battle will begin.
Step 3. Reduce Regirock's life points
Start using Fire, Flying, Normal, and Poison-type attacks. Regirock is a Rock-type Pokemon and will be strong against these attacks, so it will be less likely to defeat it before you can catch it.
Step 4. Regirock capture
When Regirock's HP is low enough, try to catch him with a Poké Ball. Buio balls are recommended; However, if you have not managed to catch him after 30 turns, you should start using the Timer Balls. Timer balls are slightly more effective than Dark balls, but require 30 or more battle turns to have been completed.
