Hello student I request you to please download the admit card again from and if you face same issue, Its recommended to wait for NTA response they'll help you for sure as it might take place because of some technical glitch.

Please contact NTA on the helpline mentioned below - Email - Neet@nta.ac.in (mailto:Neet@nta.ac.in)

Phone-0120-6895200

For more details refer to the link mentioned below - https://www.google.com/url?sa=t&source=web&rct=j&url=https://nta.ac.in/ContactUs&ved=2ahUKEwiBq_ST7b7rAhUA8XMBHZH-BZEQFjACegQICxAI&usg=AOvVaw3FFJEeb82SI-WF8kb_w1x8

Feel free to comment if you've any doubt.

Good luck