Your local city Parks and Recreation Department might have something - ours has Buddy Basketball, Buddy Soccer and some others. The Miracle League also does a baseball team in some area, might be worth contacting them as well. If neither of those works out, try your local or state Autism Society and ask them.
My son has been diagnosed with Asperger's and he goes to 'therapeutic' riding (horse back) on Saturdays and LOVES it. It is a group lesson so he is around other kids and they encourage them to talk and play cooperative games as well as work on person goals like with my son it's core strength and balance. My son was enrolled in gymnastics and karate and soccer and did not handle any of those well. It will be trial and error. As the PP said Your local Autism Society should have some great resources for you.
My son has Aspergers and he has played soccer at the YMCA. He had some good coaches that were very understanding (of his Autism), they worked with him and did a good job with him. Our YMCA has various sports and activities thruout the year. If there is one in your area you may want to check and see what they offer.
We also have a Boys and Girls Club in our area, and they offer different sports as well.
Our area has several opportunities for my ds (autism) contact your local YMCA, local special Olympics (from bowling to soccer) or your local children's hospital. My ds plays baseball on a PAL (peer assisted league). He enjoys it for the most part! GL