Maharashtra co operative hsg society

Hie,

A single building having 15 flats and 5 shops . It i registered under Maharashtra co operative society act . The society gets monthly maintenance amount from each flat and shop. My question:

1) is the co operative housing society need to file income tax return .

2) If yes which ITR has to be filled.

3) For audit purpose which all forms are required to be filled .

4) This co operative society doesn't have PAN no. does it require to apply for pan .