Amount forfeited against sale of unlisted share

DrSanjay Bindal (13 Points)

20 July 2021  
I received advance against sale of shares of my Private Limited company. Since deal could not be materialised the amount was forfeited.

Now whether this amount would be deducted from the cost of such shares, if yes from which year for the capital gain purpose, if sold afterwords.

If no, then how it would be treated ? If it is treated as straight profit then can it be set off against Long term/ short term capital gain, other income, salary or rental income etc..