Hi,
Assuming that you mean monthly paid employees then those who are in receipt of less than Rs.10000 as salary and have worked for at least 30 days are eligible to get bonus. Bonus is paid as a percentage of total salary drawn during the year.
But do not forget while computing total salary drawn during that financial year monthly salary will be taken as Rs.3500 for those who are receiving salary above Rs.3500 and below Rs.10000-.
Bonus percentage may be decided in mutual agreement between employees and employer and this also on the basis of availability of allocable surplus as per the register maintained by the employer as per Bonus act.
Regards