The examination will be conducted by UPSC for admission to the Army, Navy and Air Force Wings of the NDA for the 140th Course, and for the 102nd Indian Naval Academy Course (INAC). Candidates who are appearing in the 12th class under 10+2 pattern of School Education or equivalent exam can also apply for this exam.

Greeting,

For practice purpose you can surely give NDA in class 11. But its not that useful moreover it may become stressful preparing for it. Because it contains questions from class 12 as well.

As per the eligibility criteria of NDA, candidates must be 16.5 to 19.5 years of age. Candidates who have passed or are appearing in Class 12 or equivalent examination in any stream are eligible to appear for NDA.

For more details on NDA eligibility criteria, check by clicking on the link below:

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