you can only get rhyhorns on route 227 or stark mountain (but it's really hard to find it.)
It evolves at lv.42
you have to evolve a ryhorn from the safari zone
I think you have to migrate it. you can catch it at Stark Mountain.
Rhyhorn evolves into Rhydon at Level 42
Victory road if i'm thinking of the same pokemon
I believe a Pokemon Trainer can catch a Rhyhorn in the Safari.
You can catch one in the Safari Zone and Cerulean Cave.
You can catch him from the following places:Victory Road Floors 1, 2 and 3Safari ZonePokewalker on the Volcano Path
It wasn't available until diamond and pearl, but you can find ryhorn it the safari which evolves into rydon
You must have a protector which is located in Route 228, you must first evolve Ryhorn to Ryhdon at lvl 42 then give Ryhdon the protector to hold and then trade it with someone, trade it back and you'll get Ryperior.
in safari zone, but you will need a mach bike and maybe some pokeblocks or it will flee very easily.
No, But you can catch one in Firered and then Migrate it to Diamond