Percentage of bonus can be calculated once the balance sheet is prepared, depending upon the available surplus arrived at on a set-off formula. As suggested by the learned colleague above, bonuses are paid within 8 months after the completion of the balance sheet. Yes, you are right, many companies pay a bonus at 20% from the beginning of the company, and it is paid during the infancy period as a part of CTC. Accordingly, you can also pay a bonus (which would be called an ex gratia payment).
R R Kapoor Vadodara