If the rock is grey, you need Strength. A lot of Pokemon can learn it: see if you can teach Strength to a Pokemon. If the rock is cracked and brown, you need Rock smash. Try to teach it to your Pokemon. Good luck!
If one of your Pokemon knows Rock Smash, go in front of a rock, then tap A. It'll show a prompt asking if you want to use Rock Smash, then select Yes. The Pokemon will appear on-screen, then the rock will be shattered.
No Pokemon can evolve from an Icy Rock in Pokemon Sapphire, Ruby, and Emerald. If you are talking about the later games like Pokemon Diamond, Pearl, and Platinum, the Ice Rock can evolve Eevee into a Glaceon.
a lot of Pokemon can learn the move rock climb here are good Pokemon that should have rock climb Ursaring because it can also learn other mountain moves like rock smash machoke just like ursaring is a mountain dude geodude and its evolutions well mostly rock Pokemon hope i helped!