How Do Public Holiday Rules Apply to Our Housekeeping and Facility Management Staff?

Dear Seniors, We are a Housekeeping & Facility Management company, a private limited company, with staff working at client facilities which incur costs for the client, and staff working at the Head Office (HO) which are covered by the company's expenses. We have the following queries:

1. Which public holidays apply to both categories of staff?
2. How many public holidays are applicable?
3. Is there any legislation that specifies this?

Please help.
Regards

Dear Anil, May I know which company you are from because I also work for a facility management company. Anyways, the government notification for the holidays is attached herewith. You need to provide 10 holidays in a year, out of which 4 will be compulsory (26th Jan, 1st May, 1st Oct, 15th Aug) and 6 of your choice, for example: Diwali, Holi, Christmas, Eid, Gudi Padwa, Bhaubeej, Ganesh Chaturthi, etc.