Dear Ramdass
There are three ways to calculate the HRA :-
1. Actual HRA received
2. If you are living in metropolitan city, it should be 50% of basic, otherwise 40% of basic component of your salary
3. If you are paying rent & you have rent receipt, you should calculate "Rent paid-10% of basic"
Now, HRA Exemption = Minimum return from the above three way calculation.
I hope it will fulfill your query.
Regards,
Sanjay Gupta
9871018121