Deleted member 34656
Agree. His parents are doing the work. It appears they support his view of himself as victim. He cries, they step in.This is the key sentence. Stop doing the work. You don't say how old, but it's fair to say that the kid missed out on a maturing stage with being moved around, and is being left behind in terms of emotional development. Complaining to authority is part seeking their company and part seeking to have the other kids ordered to accept him, both inappropriate reactions.
Kids respond to motivation. You should give absolutely zero feedback when he seeks to involve authority figures - no reward, no punishment, no interaction at all. Just say something dismissive like 'I don't have time for that', without making eye contact, don't make or listen to any further comment,
At different times (so as not to be seen to as a reward for complaining) suggest small things he can do, age appropriate, for other kids his age. This will depend on how isolated he is from classmates and his age, but something like making a birthday card for a classmate. Don't make this an activity with an adult, leave him alone to do it. Tell him about the goal if appropriate, but don't harp on it.
When he makes an effort, praise him effusively, but not at any other time. Tell him that if he keeps making an effort it will work out, that it won't work every time he makes an effort, but it will work for sure if he keeps making an effort. Make it clear that the only route to adult approval or even attention is effort in the appropriate direction.
Brief other adults around - teachers, uncles, aunts and so on - on your strategy and ask them to follow it too.
My two cents.