As per the Provision of Section 16(2) of the CGST Act 2017, INPUT TAX CREDIT ( ITC ) can be claimed only when all the following FOUR conditions are satisfied :
(i). Possession of a Tax Invoice. (ii). RECEIVED THE GOODS or SERVICES. (iii). Supplier must have paid the taxes. (iv). Return must be filed.
Since you haven't received the goods from the supplier on account of Lock-Down , clause (ii) is not satisfied, hence not eligible to claim ITC now.