You bring your rabbit to the show/fair. And you have him in the coop while you wait till they start the judging. Our show we had older kids take the different rabbits to the judge to evaluate. They did the smallest groups first. Then the judge takes out the rabbit and evaluates him.
If you're talking showmanship there is a list of steps you do and each state is different.So you would have to look at the rabbit rules to see how it's done in your fair/area.