Hello

Hope you are doing fine.

I don't know which type of admit card we are talking about here. So I am trying to provide an answer which may help you.

Don't worry, you can contact your college administration and ask them to provide a copy of your admit card. As all the colleges have access to the admit cards so they would help you with this but they will charge you a small fees.

And if the admit card you have lost is of any competitive examination, I suggest you to contact the authorities conducting the exam or if you have the access to your exam application you can easily login to that and download another admit card.

Hope you will be able to get another copy of admit card. Good luck.