Best Rock Pokemon

Gym Attacker (Prestigers)

This type is one of the Best Gym Attackers, this type is super effective versus Fire, Ice, Flying and even Bug.

Tyranitar Rock Dark Max CP 3834 Attack 251 Defense 207 Stamina 225

Rhydon Ground Rock Max CP 3179 Attack 222 Defense 171 Stamina 233

These two would be all you need in terms of Gym Attackers.