You'll have to trade for one or transfer it from the older Pokemon DS games.
You can't find Steelix, in order to get one you must trade an Onix to a friend while its holding the item Metal Coat then ask your friend to give it back to receive Steelix.
You find it in the national park or when trading with Janine (any Pokemon for her Steelix).
You can find a Steelix in Route 47, Cliff Cave, Mt. Silver, or you can trade any Pokemon with Jasmine.
You get it on Route 27 inside the cave
in pokemon dp you get a steelix in olg of alpha --- The easiest way is to get an Onix, give it a Metal Coat and trade it, or trade for a Steelix from someone else. Otherwise, Iron Island is your best bet, or Victory Road or Snowpoint Temple
it doesnt.....unless pokemon brings up the next pokemon and shows steelix's evolution
Steelix
Yes; Leader Byron has a Steelix in Canvalve City.
I don't believe Steelix can be found in any dungeon. The only way to obtain a Steelix is through a recruitment Wondermail, {meaning he will join you after you complete the mission}, or by evolving a recruited Onix.
She has 3 pokemon. She has a Steelix and 2 magnimite
2 magnemite and a steelix
Steelix is a Steel and Ground type pokemon.