Property sold in F .Yr 19-20 but not taken ITR

A user sold a property in the financial year 2019-20 but mistakenly omitted it from their assessment year 2020-21 income tax return. They are seeking advice on whether they can still include this sale in assessment year 2021-22 and which financial year's cost of indexation would apply. The discussion also highlights potential issues with the property sale being conducted entirely in cash, which is problematic for tax purposes.