Installing grills

hello sir, iam from hyderabad, in our appartment HMDA building total 5 floors, each floor has 3 flats, 

1■    lift    2■   stairs     3■

1 and 3 are corner  flats ,

want to knw whether we need to take permission  to install grills for corner flat(no other flat uses that area as it is separate)

want to know whether we should take permission to instal grill for entrance nd floor wall compound also..