File a RTI with the local Police Station asking them
a) whether this kind of activity is allowed in this area?
b) Whether the Police has granted specific permission to these persons to carry on this activity?
c) If permission has been granted ask them to give you a copy
d) In case this activity is illegal then what action is the Police taking to stop this illegal activity?
e) In case no action has been taken then who it has not been taken and who is the concerned officer who should be held accountable for such dereliction of duty, kindly provide a name
You can think of other related questions so that it pushes the concerned officer to take action.
Similar RTI application can be sent, with appropriate changes, to the MCD or other authority seeking their replies.
This should get you some response based on which you can plan your next step.