As per the provision u/s 16(4) of CGST Act, Time limit to claim ITC against an Invoice or Debit Note is earlier of below dates:
The due date of filing GST Return GSTR 3b for September of next Financial year OR Date of filing the Annual Returns relevant for that Financial year.
So, in your case, You can claim ITC of F.Y 2019-20 ...till Due date of filing GSTR 3b of September, 2020 or Annual return for F.Y 2019-20, Whichever is earlier.
The last date claim of GST ITC for the FY 2019-20 is the due date for the filing of GSTR3B for the month of September 2020 or due date for filing of Annual Return for FY 2019-20, whichever is earlier.