Holiday on Parent and client company - external employee and have been posted in the Client's office

Hello, I have one query, I am an external employee and have been posted in the Client's office. My query is that if there is a Holiday on the client-side/calendar and the office is closed (while in my company's calendar there is no Holiday) am I also entitled for Holiday/off day. Please help me what the HR Policy or Laws says about this.
Thank you in advance
The company (both) referred here are multinational but the office is in India. I am posted in India and referring Chrismas Holiday.

Once client office is shut, you need to follow suit and you would also get day off. As this is a recurrent problem, suggest that as and when the Client establishment declares annual holiday you have to take up with your principal to get those days as off. The Republic Day, Independence Day, & Gandhi Jayanti has to be compulsorily holiday in India which the Principal may not be observing. So you have to properly take it up.