Capital gain query

I want to know the treatment of capital gain in the following circumstances: Suppose Mr.A is the owner of the shop and gave the shop on rent to Mr. B years back receiving a very minimal amt as rental income. Now he wants the tenant to vacate the shop but the tenant denies for the same. The case went to the court and was won by the tenant. Ultimately, Mr. A transferred the ownership of such shop to Mr. B for Rs. 5,00,000/-. However, the Fair Market Value of such shop was Rs. 50 lakh. What will be the capital gain and what amount will be treated as sale consideration for section 48 of Income Tax Act? Reply asap.