yes definitely ,please do send him for counselling ASAP.If the problem is not solved immediately, it might get worse especially since he might be a target of bullying and he is a teenager if he takes a wrong step, he might join the gangster groups to prevent himself from being hurt.I dont think he is autistic as if he is, he would have shown signs & symptoms in the early years from as young as 2 or if later your parents would have noticed something different about him by the time he was 5 years old.But still no harm sending him for diagnosis.
Also if he is in neighbourhood sch it is more likely that he will make friends with bad company and things will get out of hand.
If you are working and of adult age, you or your sisters should be able to bring him to the doctors?
Or mayb you can try talking to him someday and instead of pointing out his mistakes, point out what he has done right and tell him to keep it up.keep encouragin him
Take care and god bless.