I have a 3 year old proud-cut gelding who would do great in the rodeo as a bronc. Where can I get info?

How can I find out how to enter my horse and what the regulations are. I know they prob. aren't usually gelded, but my paint acts like a stud and although he's great with people, if someone ever sat on him he'd give them a run for thier money. Before we break him we'd like to give him the opportunity to perform just in case he's a natural. Any suggestion?