The deadline to claim Input Tax Credit (ITC) for the financial year 2019-20 is September 2020. If you missed claiming ITC in the current financial year, you can claim it in the subsequent financial year up until the filing of the September 2020 return.
If we forget to take Input Tax Credit in current Financial Year, we can take credit in the next financial year till September, next year. For FY 2019-20 , we can take credit till Sep, 2020.