The eligibility for NDA exam is determined by the conducting body i.e. the UPSC. Aspirants willing to appear for National Defense Academy Exam and Naval Academy Exam must meet the eligibility conditions as prescribed by the commission on the official notification. 

The eligibility criteria for NDA/NA exam is as follows-

1. Candidates must be a citizen of India.
2. Only Male candidates are allowed to apply for NDA exams.
3. Candidates must be of the age group 16.5 years to 19.5 years.
4. Minimum education qualification is 12th pass under 10+2 pattern of school education or equivalent for Army Wing of NDA. 
5. For the Air Force, Navy and Naval Academy of NDA, candidates must pass 12th pass under the 10+2 pattern of school education with Physics and Mathematics conducted by a State Education Board or a University. 

The UPSC determines the NDA selection process as well as the syllabus of the examination. Generally, the exam pattern and syllabus of NDA exams remain the same every year. 

The NDA Selection Process goes as under –

• NDA exam is conducted in two stages – Written Exam and SSB Interview. 
• UPSC holds the exam recruitment for NDA while SSB conducts the interview round, thus called SSB interview.
• The written exam is conducted in two parts  – Mathematics and General Ability Test. The total duration of the paper is 5 hours.
• GAT is further subdivided into two parts – Part A is English paper and part B is General Knowledge paper.
• The Total of NDA written exam counts to 900 marks i.e. 300 marks for Maths and 600 marks for GAT.
• The papers in all the subject cob=vered in NDA syllabus consists of objective type questions only. The question paper of Mathematics and Paper B of GAT is set Bilingually i.e. in both English and Hindi language. 
• The SSB Interview is also conducted in two stages and carries 900 marks. 
• Stage I comprises of Officer Intelligence Rating (OIR) tests are Picture Perception * Description Test (PP&DT) and Stage II Comprises of Interview, Group Testing Officer Tasks, Psychology Tests and the Conference. These tests are conducted over 4 days.