Suggest me the correct treatment

Dear Colleagues,

Your suggestions required on the following.

Lets say a person has a property of Rs. 5 Lacs in his Balance Sheet. If the same is sold to other person for Rs. 25 Lacs. Now if the person receives the payment of Rs. 10 Lacs & the purchaser is not able to make any further payments. Rs. 10 Lacs is now forfeited by the seller. The question is what should be the treatment of this Rs. 10 Lacs? Please mention the provision & case law if you cite. Also, tell me the treatment if the same is sold for 7 Lacs?

Thanks in Advance