HRA higher rent submitted

Hello All

On behalf of my friend.

For last FY (21-22), he showed higher rent amount compared to what actually paid and submitted to the employer. Employer have deducted tax accordingly. Now the HRA amount showing as income against landlord PAN. Landlord is saying he is going to reject this as this is resulting in higher tax burden on him. 

Now what would happen? Will income tax department send notice to my friend or his employer? If his employer, what would be the next course of action? If my friend, what would be the next course of action?

Thanks