Hello Nayana,
The requirement is as follows:
* Establishments employing 20 or more persons and engaged in any of the 180 industries / Classes of Businesses specified.
* Co-operative Societies, employing 50 or more persons & working without the aid of power.
* Establishments not coverable statutorily can come under the coverage of the Act statutorily.
* An establishment continues to be covered under the Act, irrespective of the fall in the employment strength.
* Since the Act applies on its own force to the establishments, the employers are required to file the particulars in the specified format for registration and allotment of business number.
You may visit the Office of the RPFC in your city (if you are in state capital) or visit
EPFO <link updated to site home> for further details.
Good luck.