HEY,

NDA stands for NATIONAL DEFENSE ACADEMY. It conduct its exam twice a year in order to admit students into different field of defense like army, navy, aur force etc.

As per the past trends, you need to score around 400 or more in order to be safe for your SSB call letter.

Apart from that sectional cut off, that is, 25%in each section should also be fulfilled.

Hope that helps.

All the best.

Thank you