Confused About Bonus Calculation in Excel? Need Help with the Right Formula!

I need help with bonus calculation. This is my Excel sheet:

Name DOJ Basic

Now, what should be my formula for calculating the bonus for these employees for the last year? I'm a bit confused with the concept. If anyone can clarify, it would be greatly appreciated.

Bonus Calculation Steps

Basic amounts or Basic+DA are paid to the employee for all the months from April/May/June through to February/March.

a) Then add these amounts employee-wise.

b) Multiply the total by the percentage decided by you.

c) You will arrive at the bonus payable amount.