Mr Kannan's point is very valid. It would be necessary for the Govt. to issue immediate instructions (giving wide publicity) that while making an investment for Sec 80C benefit - e.g. PPF deposit - between the period 1.4.2020 to 30.6.2020, the depositor should have to specify in writing on the application form the FY in which the deposit should be accounted for. Applications without such specific mention should not be accepted. The institutions accepting the investments should also enter (against the relevant entry) in all the related documents - such as passbooks, fixed deposit receipts, mutual fund statements, etc. - the financial year for which the investment relates to as desired by the investor.
Further, in the Income-Tax Return forms for AY 2020-21, the I-T Dept. should include a column for the assessee to enter the date(s) on which the investment was made for this AY. A similar column may be incorporated in the ITR for AY 2021-22 for the investment made for that AY. This would enable the Dept. to check whether an investment made between 1.4.2020 and 30.6.2020 is claimed a second time . (In this case, it is still possible, though, that an investor might invest two amounts on the same date between 1.4.2020 and 30.6.2020, one for AY 2020-21 and the other for AY 2021-22, but the assessing officer would be put on guard!)