For some inexplicable reason, these folks are desperate to be sidekicks to currently existing super-heroes. Maybe they figure it’ll give ‘em a leg up in the business. They include both super-hero groupies, and the (more dangerous) sidekick wannabes who try to sneak in on the action.
The above came from the original, 2005 vintage canon information seeded into the old Wiki as starter material. The Robins apparently do not exist as a clique or club, partly because very few heroes (more villains) operate as solo operators with sidekicks. The Kid Sidekick Laws prohibit the practice in any case, at least in the U.S.
Also, a lot of students apparently use the term Robins in a derogatory sense for groupies.