There is a situation which one of my friend (a tenant) is going through in Dubai

My Friend has rented a Shop in a Shopping Mall located in Dubai - Bur Dubai from past 4 years which was running in losses.

From 10 months the customers have raised and he was doing the Breakeven.

Suddenly the Mall is sold and New Landlord is asking for New RENT 40% increase and he is showing a document of RERA stating landlord can increase the Rent to Market Rates.

My friend has put all his money in the business and may go bankrupt incase the situations goes out of hand.

Is there any Rent index for the Commercial properties declared in Dubai ?

Does the new Land lord has right to increase 40% just like that

Please help