Where are all the Regis doors and how many are there?

They are in the desert, the surf spot between Petalburg and Dewford, and near lilycove but past the Safari Zone. There are three.

There are 3 Regis. Regiice, Registeel, and Regirock. Once you craked the code of the Sealed Chamber, you can get them. Regirock's located in the desert. Go into the desert and head south. Keep on going until you see a pyramid shaped rock with an entrance in it. Then go in there and solve the braile question. Then go to Mr. Briney's house.

Surf down and along the left edge until you see an island with trees. Go onto it and go to the other side. Surf up until you get to the pyramid shaped thing with the entrance. Go in and solve the question to get Regiice. Then go to Fortree.

Go right and keep on going south. Past the scorched slab, past the rainy area, past the bug catcher, all the way down to the girl who gives you a figy berry. Then go up, past the grass and go to the pyramid shaped rock. Solve the question and !Viola!

You got the 3 Regis.

3 regis three doors the doors have to be opened by go to pacilog town and going at the bottom of the waves until you come to a place where you can dive, once you go down there you will have to go a little ways and then when you come to dots on the wall dive up go to the end of the room you came up in and use dig in the next room.

Go to the end and have a relicanth in your first party slot and a wailord in the last and read the dots on the wall and you have just opened the doors to the regis~~~~~~~~~ regirock is in the south end of the desert and when you go into the chamber go to the center and go 2 steps right and 2 steps down and use strength the wall will open and when you go in you wwill see regirock for bring lots of ultra balls~~~~~~~ regiice is in a tropical island of the northwest of dewford town once you get there you have to read the dots and wait 2 minutees and the wall will open.

Registeel is west of lilycove city go all the way left from lilycove city and go up once you come to some stairs and you should find a chamber once your in there go to the center of the room and use fly the wall will open.

Hope this helps.

There are 3 doors in total. One door is at the desert with the sandstorm going on all the time. It holds the rare Pokemon Regirock. Another door is at the lower part of Route 120. It holds the rare Pokemon Registeel. The other door is at Route 105. It holds the rare Pokemon Regice. You can catch them in any order.