Industrial Standing Order for Factories
I think that you must follow the Industrial Standing Order for the factories. In such cases, the leave policies are as follows:
"A person employed in a shop or an establishment shall be entitled—
1. For every completed year of continuous service, to privilege leave on full pay for fourteen days.
2. In every year, to sick leave on half pay for fourteen days on a medical certificate obtained from a medical practitioner.
3. In every year, to casual leave on full pay for ten days.
4. In the case of women, to maternity leave in accordance with such rules as may be prescribed.
In each week, every shop or commercial establishment shall remain entirely closed on, and every person employed in a shop or an establishment shall be allowed as a holiday, at least one day and a half day with full wages. Also, on National Holidays that are declared by each state separately, employees must be allowed holidays with full wages. The periods and hours of work for all classes of workers in each shift shall be exhibited in English and in the principal languages of workmen employed in the establishment on notice-boards maintained at or near the main entrance of the establishment and at the time-keeper's office, if any." Read full here
Drafting of HR policies in line of Industrial Dispute Standing Order
Maharashtra Shops and Establishment Act
In the case of offices, follow the norms of the Maharashtra Shops and Establishment Act. It states that it does not cover factories. It also says as follows:
Every worker shall be entitled to eight days of casual leave with wages in every calendar year, which shall be credited into the account of the worker on a quarterly basis but shall lapse if unavailed at the end of the year.
Every worker who has worked for a period of two hundred and forty days or more in an establishment during a calendar year shall be allowed, during the subsequent calendar year, leave with wages for a number of days calculated at the rate of one day for every twenty days of work performed by him during the previous calendar year.
Every worker who has been employed for not less than three months in any year shall, for every sixty days on which he has worked during the year, be allowed leave, consecutive or otherwise, for a period of not more than five days.
Every worker shall be permitted to accumulate earned leave up to a maximum of forty-five days.