Employer not approving the annual leaves

I had informed a month prior to my scheduled annual leaves of 1 week. But my HOD is continuously refusing to provide approval on the leaves even though I have requested him many times. Even though they are continuously saying that year end is a critical time to provide leaves when the leaves are required to be availed but he has all the required personnel to manage the work in my absence. But he is rejecting the leaves request blindly saying no leave shall not be given to any employee during that time. He has been playing politics along with his subordinates and making a performance issue against me for the past few months even when there is no performance issue with me. They are specially targeting me and trying to spoil my image in view of sacking my job. Now when I already have done the reservation for the trip, they seem to have got a strong point against me to stuck me on this leave issue so that if I take the risk to go for leaves without their approval then they will immediately fire me. HR also refused to extend any help also. I want to know that as per Indian labour or industrial dispute laws, being a female do I have a strong case against the harassment done to me by my employer due to the issues so far and also due to this leave issue if I do go for my leaves without the approval of my employer or whether do I have any right to go for leaves if I have leaves balance in my account and the work can be managed without me for a week.