Okay I found this forbidden cave and unlocked the doors to the regis and..

For Regice you need to go in a complete circle around the room after reading the braile without hittin' the walls.

Registeel you need to read braile, go either 2 to the left or right, then down 3 or 3 left or right then down 2. I can't remember too well 'cause it's been a while.

Regirock you use dig in the middle of the room after reading braile, I think. I'm not too sure about this one.

These colud be a bit mixed up but I tried.

-SGX

The bunch of dots are called braille. I don't quite remember what they mean, but I'll try. Give me credit for at least trying, ok?
For the one on route 105... Regice's lair... I think you have to run around the room once touching the walls but not bumping into them.
For the one on route 111 (Desert)... Regirock's lair... I believe you go "right, right, down, down" and in that spot you're in, you use rock smash.
For the one on route 120... Registeel's lair... This I know. Go to the center of the room and use flash.
I really think I got them right. If I didn't, well... Sorry for that. Rate this answer.

Well the dots are like what the blind people use to read. Just look on the internet to learn how to read braille and it will show you how to use like the dots. Or you can by the Pokemon emerald guide book.

Try to use nest ball (found at Verdenturf town) everyone thinks it's for weak low levels but it actually works on weakened Pokemon like if it's on red then use a nest ball. I caught my friend a rayquaza with it and it was on orange.