reggi,s

First to unlock the chance to catch all three of the regi's you will need the following things. 1. A wailord in your lead position and a relicanth in your last position
2. You will need a Pokemon that knows dive a Pokemon that knows surf and a Pokemon that knows dig

Next you have to find the sealed chamber. It is on route 134 their is a small place where you can dive. When you find it dive and continue down until you see a wall that has visual brail on the south side use dive when you are infront of the brail. This will lead you into the sealed chamber. There will be 9 or 10 walls in here these walls are just the alphabet. On the north wall is another message. Use dig right infront of the brail. It will take you into another room. Once there you will see another message in brail on the north wall this will say to put wailord in the first and relicanth in the last but you have already done that so the ground will shake and open up three new caves all over the region. Hope this helps good luck on the catching all of the regi's

PS once you do this each regi cave will have brail in it and you will have to do what it says to open up the doors.

Sorry it took a while but I started my sapphire over and just got the regis
But anyway the message on registeel wall says "with new time. Hope and love. Aim to the skyin the middle." translation fly in the center of the room

The message on regice wall says "stop and wait, wait for time to pass twice."
Translation click on the wall and wait for two minutes.

The message on regirocks wall says "right, right, down, down. Then use strength
No translation needed

Hope this will help you

To get the Regi's you first have to have both Wailord, and Relicanth. Once they are in your team, head to each of the Chambers, and you will see some Braile. Fireguy has already told you what each of the sets of Braile say in the chambers.