Hi,

No need to worry , even though you lost your admit card , you can download it from the official website again. The link is still active and you can download it from the official website, link is provided below:

https://ntaneet.nic.in/ntaneet/AdmitCard/AdmitCardNEET_ALL.htm

There have been incidences when students either forgot their admit cards or lost them during counseling. You can simply download it and present it at time of counseling.I would recommend you to always keep a scanned copy of your important documents regarding counselling in your email , to be always on safe side.