Empler not paying on Christmas

I have a question regarding my employment. My employer is X and I work for client Y. Y is a German bank. We X employees sit at client location but in India. X employees get paid on hourly basis. During Christmas there is no work in the office. So Y has declared holidays for X employees. That mean Y won't pay X for 15days during Christmas. So X employees don't have to go to client place and work. So now X is also denying to pay salary to their employees and asking to remain at home. Also they are saying if you want to get paid during those days then apply for the leave, you will get paid for leaves applied days. I think according to employment law this is incorrect. As I am permanent employee of X they should pay the whole month salary even if client is not paying them. Please advise