I would suggest you to prepare the maths first from NCERT books because most of the quetions generally come from NCERT books. Here you can follow  the preparation tips for other topics:

Class 12th books must be referred for Mathematics, Physics and Chemistry sections and Class 10th books for Biology, Geography, History, Political Science, and Economics.

Create a revision sheet for Mathematics. It should have important points and formulas.

Revise basic grammar rules in order to score high in reading comprehension, basic grammar and vocabulary

The English section for 200 marks is one of the most scoring sections in the NDA examination, so it is  important to prepare for it well

You must be aware of the current situations and be prepared for Environment Science and General Science

You must have knowledge of India’s struggle for freedom, Constitution of India and the political scenario of India.

Current Affairs is one of the most important sections in the entrance exam. You must be well aware of the events that took place,

Practice at least one sample paper before sitting for the exam. This will help in understanding the exam pattern and bring better clarity on how to attempt the same.

Good Luck!