Confused About HRA Percentages: Can Employers Set Their Own Rates for Salaries?

Hello Seniors, I am currently studying HR through correspondence and need your help on a topic I am confused about. Can the HRA be any percentage of the basic/gross salary? I mean, can an employer pay, say, 10% or maybe 15% of the gross salary as HRA, or does it have to be a minimum of 40% of the basic pay for non-metros and 50% for metros? I am so confused about this, so please help. Hoping for a reply soon.

HRA Percentage for Metro and Non-Metro Cities

HRA is 40% of the basic salary for non-metro cities and 50% of the basic salary for metro cities. For any clarification, feel free to write or discuss.

Regards

Dear Prasenjit, Thanks for your reply. That's what I think too; it is 40% - 50%. However, a friend of mine receives an HRA that is 18% of his basic salary. He works in a town in UP. I am getting more confused. Please help.

Regards,
R Kumar