Dear Candidate,

As per the basic eligibility criteria of NDA , any student whose age lies between 16.5-19.5 years, is eligible to give this test. And also, he/she must be either in 12th or had passed the 12th class. Now clearly your age is 18.6 months, hence you are clearly eligible to give the NDA Exam.

NDA Exam is conducted in two phases. One in April and other in September. So, you can easily give both the April and September session Exam. There will be no difficulty in that.

Hope it helps.