Autism is definitely a big bucket of diagnoses, everything from we-honestly-don't-know to Asperger's. Since this is a very wide-ranging family of diagnoses the available therapies are also wide-ranging in methodologies and effectiveness. Autism therapy is more about teaching them how to deal with the outside world rather than making them act differently or "normally," whatever that means.
I have 2 sons with autism, both high functioning and one of them was also diagnosed with Asperger's. Neither is a "prodigy" but both are absolutely on-par with their peers in terms of intelligence. When you look at social/emotional maturity they are 2-4 years behind.
In the case of my boys, group therapy didn't work very well. The best thing for them so far has been ABA therapy-
http://www.autismspeaks.org/what-autism/treatment/applied-behavior-analysis-aba
They spend 4 hours per week in ABA therapy doing occupational and speech therapy which they have been doing quite successfully for about 4 years now. Social interactions are still painful with neuro-typical peers (yes, "neuro-typical" is how their doctors refer to "normal" kids).
An example from last week- At a park playground with my kids, one son walks right up to a woman (never seen before or since) and dead-pan tells her, "Your dog is ugly." She grabs his arm and drags her over to me demanding an apology.
Me: "Did he shout at or harm your dog in any way?"
Her; "No, but what he did was not right."
Me: "You're right. He does deserve an apology. Are you going to apologize to him for physically dragging him over here over something as minor as insulting your dog?"
She just stared at me with her mouth open and then walked away in a huff.
Schools are a very sore subject with me. School staff (teachers, administrators, para-educators, etc.) are either incredibly gifted with special-needs kids or they are completely inept: there doesn't seem to be a middle ground. Be prepared to (calmly) escalate concerns to people higher up the chain of command in your district and be prepared to go all the way to the superintendent, office of ombudsman, or state superintendent of public instruction (person in your state in charge of education, if in the US. no idea who this would be outside US). Be prepared to go school shopping to find one that better meets your needs.
One more word of advice: look for an autism support group in your area. Even if you don't go to regular group meetings they are a great resource for finding local therapists, finding strategies for navigating school district bureaucracy, and finding different types of therapies (music, nature, etc.).
There is no magic bullet here but there are a lot of different ways to approach Autism.