The EWS certificate is valid for one Fiscal or Financial year. If your ews certificate is issued on October,2021 then its valid for the fiscal year 2021-22 i.e., it was valid till 31st March, 2022.

Now for this year, you have to apply again for a new certificate by following the same procedure as before which will be valid for the fiscal year 2022-23.

I hope this helps. Wish you a great eve!