See if you have provided that the EWS applicable, then you should keep the certificate with you. Because, you may get the job through Unreserved category, but if they ask you to produce it, then you will be in trouble. So my suggestion will be that, if you have the time to get the certificate/if you have the certificate, then take it with you during the document verification. Although, if you get the job through UR category then you will not find much a problem if you don't have the certificate, although it would be better for you to take the certificate with you, in order to have a better career ahead.

I hope this helps. Wish you a great day!