As per the eligibility to apply for NDA, For Army Wing of National Defence Academy - Candidates applying for admission to the Army wing of National Defence Academy should have passed Class 12.

For Air Force and Naval Wings of National Defence Academy and for the 10+2 Cadet Entry Scheme at the Indian Naval Academy - The candidates must have passed class 12 with Physics and Mathematics conducted by State Education Board/ University. You can check the further information with the given below link.

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

Here are some preparation tips you can follow:

Prepare mathematics with the help of the basics of class 9,10,11,12. If you are done with the basics start practicing from a good book.  Be consistent with your preparation.

General Ability Test consist of two sections-English and General Awareness. The English section can be tackled by practicing questions such as error finding, fill in the blanks, Jumbled para, reading Comprehension etc.

For general awareness you need to study the social studies of class 9th and 10th and current affairs. You need to read newspapers for the current affairs.

The weightage of the general awareness section is very high so you need to be more focused on current affairs.

Join mock tests to analyze your preparation.

Good Luck!