It is not a problem. Since nowadays all the exams and the processes are online, you don't have to worry about that. You will be getting your admit card from the official site. Just login by entering your application number and password. Your admit card will be available in your profile and download it. After that you have to go to an internet cafe and take print out. If you have applied for the exam then your admit card will definitely on your profile in the official site.

https://jeemain.nta.nic.in/