We have home schooled kids playing on the High School teams. I’m not sure how rare it is, but I’ve heard some parents speak of difficulty coming to arrangements with schools. Some allow it and some don’t. Check with the schools in your area. You may need to check with several. For schools that allow it, there is some sort of documentation required for the school and some waivers to sign for insurance purposes so they are protected against various liabilities. I really don’t like AAU because I think it’s a scam, but that’s an option. There are also club teams for towns that have players of all age groups and they sign up to play in area or regional tournaments all summer.