Hello Nikita,

There are some boarding schools that prepare students for NDA along with their schooling. Like - Defence Academy Dehradoon, Rashtriya Indian Military College, Rashtriya Military School Bangalore.

But, I will recommend you to please start reading books for the exam preparation on your own for some time.

For more information on NDA exams, please go through the following links:-

https://competition.careers360.com/exams/nda

https://www.google.com/amp/s/competition.careers360.com/articles/best-books-prepare-for-nda/amp