What is the nature of your industry? We need to know to this to find out whether you are registered under Factories Act or Shops and Establishment Act. Please refer either of the act, as applicable, and design the leave policy. You may give more number of days of leave but not less as specified in the act.
While designing the policy, please include definitions for "Leave", "Closed Holiday", "Weekly off". Out of ignorance, employees use these terms interchangeably, however, it is wrong to do so. Going further, please clarify definition of "Leave Without Pay" (LWP) and "Absence".
In the policy, include entire process of the movement of leave application. Clearly specify who is the approving authority for whom.