In case of SC certificates , you are not required to renew it for JAC Delhi. Only OBC-NCL cetrificates are required to be issued after 31st March 2019, if it is prior to the date then an additional certificate is required representing the current non-creamy layer status.

You can go through the reservation section provided in JAC delhi information brochure 2019. https://jacdelhi.nic.in/publicinfo/Handler/FileHandler.ashx?i=File&ii=252&iii=Y