Yes, the candidates who have passed class 12 th from open school can appear for NDA exam. The age of the candidates must be 16.5 to 19.5 years of age and must have completed or appearing in class 12 th can apply. To check more details about NDA eligibility criteria, check the link given here - https://competition.careers360.com/articles/nda-eligibility-criteria
Eligibility recruitment for NDA is different for two different wing:
Category 1: For Army Wing of National Defence Academy : Should have passed Class 12.
Category 2: For Air Force and Naval Wings of National Defence Academy and for the 10+2 Cadet Entry Scheme at the Indian Naval Academy:
must have passed class 12 with Physics and Mathematics conducted by State Education Board/ University. Candidates appearing in Class 12 or equivalent examination are also eligible to apply for NDA 2019. However, those appearing/ passing class 11 exams are not eligible for the exam.
You are eligibile for 1st wing but not for the second