will there be any problem if my sign is not appeared in my admit card ? and the nta athorities are not replying to my mails and calls

Dear Shruti, please check if you used the email id neetug-nta@nic.in. They usually take a time of atleast 48-72 hours before they reply. Your signature needs to be shown on the Admit card. This is important to authenticate your identity in the examination hall. So please wait to hear from them atleast for a day or two. If they dont respond, you can mail them again, attaching the copy of your admit card.