I sold shares in F. Y 2019-20 which i purchased in1999 but i dont knw the purchase price. How should i calculate capital gain and what should i take cost of acquisition.
Google for average stock value for FY 1999-2000. Look at low, high and close values as on 1st April 1999 and 31st March 2000. See which is the most appropriate one to your case.
Apply grand fathering rule under sec112A actual cost of purchase or MP of share as on 31st Jan 2018 which ever is higher will be deemed cost of purchase