You'll have to trade it from another version. It is available in Pokemon Emerald at the Desert Underpass (Near Fallarbor), and many places in versions Fire Red and Leaf Green.
You can't catch Ditto in Ruby. You have to trade it from Emerald, Fire Red, or Leaf Green.
You can't catch Zekrom in Ruby version.
You can't catch a sentret in Ruby version, but you can catch one in Emerald version.
You cannot catch Ponyta in Ruby version, nor Sapphire version. You much catch it in Fire Red or Leaf Green and then trade it to Ruby or Sapphire.
No.
you find it in the giant chasm
No you can't catch darkrai in ruby unless you hack (witch i do not recommend)
You have to trade them from the Sapphire version of the game.
iv'e been all over the region and never EVER seen a ditto and btw im at elite 4
master ball
We get vulpix in MT.PYRE
No, but you can catch one in Emerald after the Pokémon League.