Dear Friends,
I may be wrong in giving answer to the querist.
Indeed, the query is wrongly put, according to me. The querist, I feel, wanted to ask whether house rent allowance is MANDATORY only in Maharashtra or in other States also.
Therefore my answer was - some of the States are having a law for minimum HRA.
This means, in those States it is mandatory to pay minimum HRA to the employees. In rest of the States, it is not binding on you to pay HRA.
And therefore I disagree with the statement by our Senior member Shri. Pon - "It is applicable throughout India".
Though it is not binding on you to pay HRA, you can pay it. If you pay it, the employee can avail IT exemption on this payment under certain circumstances as per section 10 of IT Act.