Hi Ankita,
Others can only suggest some standard policy but you should be able to customise it. Before implementing the policy try to get the feedback of line managers, employees and investors.
Type of leaves- Casual Leave, Privilege Leave, Sick Leave, Marriage Leave
Leave crediting- monthly or annual basis
Provilege leave can be accumulated and carry fwd to next year
If you are not satisfied with the already received policies get back to me, i can help you to formulate one
I would suggest you to automate the leave system
regards
Sreekumar.J