greetings,

Since you have not mentioned the state you belong to I'll mention some basic information as released till date:

admit cards for NTSC are released state wise with some states releasing it online (for download) and some states releasing it offline (to be distributed through schools)

So far, MP, UP, Bihar, Maharashtra, Kerala and UT of Delhi have released their admit cards and the other states will soon follow

(this is because some states will conduct the examination with delayed dates and hence the delay in admit cards as well)

I am attaching a link where you will find all the official state websites through which the notification about NTSC admit cards or the card itself would be accessible,

https://school.careers360.com/articles/ntse-admit-card

hope it helps,

good luck