Firstly I would suggest you to go through well with NCERT books, it will help you to clear your concept then you can prefer other books given below.

Physics: Concept of Physics by H.C. Verma Fundamentals of Physics by DC Pandey,  Problems in Physics by I.E. Irodov

Chemistry

You can refer Arihant Publication book for NDA. In addition to it for your Genaral ability and general knowledge part, refer to the class 10th books of Social Science and Science, which will cover you history, civics, political science and geography part, and the other one will cover you physics,

You can refer Arihant Publication book for NDA.

In addition to it for your Genaral ability and general knowledge part, refer to the class 10th books of Social Science and Science, which will cover you history, civics, political science and geography part, and the other one will cover you physics,

As the exam is being conducted by CBSE, thorough reading of the NCERT (National Council of Educational Research and Training) textbooks is must. The content of NCERT books should be read completely and figures given should be understood minutely. You must solve the exercises given in the NCERT books. It

• Algorithms:  Introduction to Algorithms by Rivest, Cormen, Stein, Leiserson.
• Operating System: "Operating System Principles" by Galvin.
• Theory of Computation: "Theory of Computation" by Ullman. Good for interview preparation as well.
• Computer Networks: "Computer Networking: A top-down

Yes, there are coaching courses for two months which you can opt for. If you want to crack these exams make sure your concepts and fundamentals are clear. You can take help of NCERT books for that

You can also below strategies to crack these exams

1- Know the complete

In order to crack JEE Main in 4 months you should be aware of syllabus, exam pattern and important topics. Focus on the topics which carries more weightage in the exam. You can refer previous year papers to understand the exam pattern and level of exam. You can solve MCQs