The bonus for the year 2024-25 shall be paid in 2025-26 only. This year, you can pay the bonus for the FY 2023-24. The resigned employee who has worked for at least 30 days in the financial year (2023-24) is also entitled to receive a pro-rata bonus for the days worked.
It is not necessary to pay any ex gratia amount unless it is part of the service condition, i.e., part of the CTC on which the employee was appointed. You can restrict the payment of bonuses to those who are within the bonus bracket of Rs 21,000 or less (not above Rs 21,000). However, if you have included a bonus element in the remuneration structure (CTC) of all employees, including those who are not entitled to a statutory bonus, then you should pay it.