Since his basic salary and DA combined are less than Rs 21,000, he is eligible for a bonus. You can calculate the bonus payable based on the minimum wages set by your state government. For instance, if the minimum wages applicable to the same employment in your industry are Rs 12,000, you should calculate his bonus as if his salary is Rs 12,000. If your organization falls under a category where no minimum wages have been established by the government, then you can calculate the bonus as if the salary is Rs 7,000 per month.