Sir you can file Divorce on the ground of cruelty by mentioning specifically about she left u and 6years child ..and not ready to take care of Autism son..and if possible collect all call records..that they are telling lie to child that his mom gone for some work.. and these proofs submit in the court at the time of evidence..and take divorce and if she claims any kind of alimony or maintenance.. don't give single pany to her .for more clarification u can connect with me.