Hi. You have stated that your boy is unable speak and walk without support. Where ever you are you can visit a rehabilitation clinic with occupational therapy and speech therapy given centres. If you can take him there, they will assess your boy and will give therapy. Slowly your boy will show improvements based on the problem he has. Nowadays many parents take their kids there and get improvements and well trained. It helps children greatly. Also other therapy like physio and concentration and behavioural issues are treated by therapists. So pls dont hesitate to take the boy and find out wats the issue.