Almost every state has 3 unbound delegates, usually state party officials. A couple states send all of their delegates "unbound". It is not nearly as many as the Dems do, but there are enough that it could make the difference in a close race.
Both Iowa and South Carolina binds their three “unbound” delegates to the presidential preference vote. The three are the state party chair, and the male and female (mandatory one each) national committee members.
They are not necessarily unbound delegates (it varies by state), but they are automatically delegates.