It is a difficult situation that you are describing and something many parents across urban cities going through.
ADHD when untreated or partially treated can lead to and associated with severe conduct related issues which peaks in late adolescence and early adult hood.
Having a trusting and confidential relationship helps the person struggling to evaluate the choices they make.
Next Steps
Can he be spoken to by a person he trusts on regular basis?
Can he be encouraged to develop a routine even if it is for few hours that is healthy. Physical activity or learning new skill in a youth setting ?
Maybe if he can be coaxed to see a professional who can also evaluate need for medication
Health Tips
Keep trying to focus on positives and develop family routine that keeps positivity in relationships.