Dear Ekta,
I believe your establishment is located in Maharashtra, and therefore, you should follow the minimum requirements as provided in The Bombay Shops & Establishment Act (for the whole of Maharashtra). More days of leave can also be considered, but you have to comply with the Act's provisions. When declaring holidays, you should follow the holidays announced by the state government for each calendar year. The minimum requirement is 3 national holidays, and you may decide on other local state holidays at your discretion. The extract of leave rules from the Act is as follows:
CHAPTER VII
Leave with Pay and Payment of Wages
35. Leave. - (1)(a) Subject to the provisions of clause (b), every employee who has been employed for not less than three months in any year shall, for every 60 days worked during the year, be allowed leave, consecutive or otherwise, for a period of not more than five days. (b) Every employee who has worked for not less than two hundred and forty days during a year [irrespective of the date of commencement of his service] shall be allowed leave, consecutive or otherwise, for a period of not less than twenty-one days. Provided that such leave may be accumulated up to a maximum period of forty-two days. The leave allowed to an employee under clauses (a) and (b) shall be inclusive of the day or days during the period of such leave on which a shop or commercial establishment remains closed under subsection (1) of section 18 or on which he is entitled to a holiday under subsection (1) of section 24 or section 31.
If an employee entitled to leave under subsection (1) [or (1-A)] is discharged by his employer before being allowed the leave or if, having applied for and been refused the leave, he quits his employment before being allowed the leave, the employer shall pay him the amount due under section 36 for the leave.
If an employee entitled to leave under subsection (1) [or (1-A)] is refused the leave, he may give intimation to the Inspector or any other officer authorized by the [State] Government regarding such refusal. The Inspector shall enter such intimation in a register kept in the prescribed form. The employee shall also send a copy of such intimation to his employer, and therefore, the employee shall be entitled to carry forward the unavailed leave without any limit.
Notwithstanding anything contained in this section, every employee, irrespective of his period of employment, shall be entitled to additional holidays on the 26th of January, 1st of May, 15th of August, and 2nd of October every year. For holidays on these days, he shall be paid wages at a rate equivalent to the daily average of his wages (excluding overtime) earned during the month in which such compulsory holidays fall. The employer may require any employee to work in the establishment on all or any of these days, subject to the conditions that for such work, the employee shall be paid double the amount of the daily average wages and also be granted leave on any other day in lieu of the compulsory holiday.
36. Pay during leave. - Every employee shall be paid for the period of his leave at a rate equivalent to the daily average of his wages for the days on which he actually worked during the preceding three months, exclusive of any earnings in respect of overtime.
37. Payment when to be made. - An employee who has been allowed leave under section 35 shall be paid half the total amount due to him for the period of such leave before his leave begins.
The bare act of this Act is attached. You may refer to it, get it updated, and use it.