Late in August or early in September, call the district or region that governs the school you would like him to attend and ask if there is a schedule for visiting schools and applying for a variance. Lately there is limited opportunity to attend out of zone. Some districts hold a lottery for any available places. If you are denied a variance, you should speak to the zoned school principal and or guidance counselor to discuss your concerns about the level of challenge and how the school can accommodate your child's needs.
You can find out the district and region by logging on to
www.insideschools.org