Hello Bal Krishna!

Yes, you're eligible to apply for the NDA NA examination.

You should be able to submit proof of passing the board examination with the original certificate at the time of the SSB interview.

You can also appear for this exam after your boards

Good luck!

Hi Bal

Here are the insights into NDA exam 

Eligibility 

1. Nationality

A. Citizen of India or

B.  Subject of Bhutan or

C. Subject of Nepal

2. Age limit

The candidate should be between 16.5 to 19.5 years old. 

3. Martial status 

Only unmarried candidates are eligible for NDA

4. Educational Qualification

The candidate must have passed 12 with maths and physics.  Candidates appearing for class 12 are also eligible for answering NDA

If you fullfill all the criteria from above you are eligible for answering NDA

For more details go through this link 

https://competition.careers360.com/articles/nda-eligibility-criteria

Registration Date:  09 Jan to 04 Feb 2019