i am eligible for ews but currently i don't have ews issued after 1t April 2022 then what should I upload during jee advanced registration

If the candidates belong to any reserved categories they are required to upload that category certificate at the time of registration.you can apply for JEE-Main 2022 even if you don't have category certificate because if you belongs to either OBC-NCL or EWS category then there is a provision of self undertaking/declaration submission in lieu of category certificate for aforesaid categories. If you are eligible for EWS category, If you do not possess a VALID OBC-NCL/EWS certificate issued after April 01, 2021, you may submit a declaration in place of the certificate.However, you MUST upload a VALID certificate (issued after April 1, 2021) by October. Then it is fine.
Thank you