It’s unclear what role Leonardo DiCaprio was auditioning for, he would have been about 15 at this point, which makes it unlikely he was looking at the role of Jack, the son of Robin Williams’ character. He would have been significantly older that Charlie Korsmo, the actor who got that role. It’s more likely DiCaprio was looking for another part. Perhaps he would have been one of the Lost Boys. Can you imagine Leonardo DiCaprio as Rufio? Dante Basco, who got that role, is slightly younger than DiCaprio, so that looks like a better fit.