You can't you will have to trade from leaf green or fire red
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.
In the dark cave or victory road.
there are no steelix in saphire,emerald and ruby version. hope my answer can help you! if you want to get a steelix you have to give an onix a "steel coat" and via trade it. after you trade it, it will automatically evolve.
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.
You catch Onix in Orbeghuh Mines or on Iron Island
master ball
We get vulpix in MT.PYRE
No, but you can catch one in Emerald after the Pokémon League.
Find the crystal onix, make it weak and catch it with your best ball