Dear Neha,
For bonous;
1. The first thing for eligibility for bonus is that the employee should be worked for 30 working days in that year.
2. Minimum bonus limit is 8.33% of basic upto Rs.3500/-. But the company can allow more than this also. That depends upon the company.
3. If basic is more than Rs.10000, then the employee is not eligible for bonus. But, if the management wants to pay bonus to that employee, then it will treated as "EX-GRATIA".
Hope, this will help you in understanding the matter of Bonous.