how can a student prepare for jee without any coaching or for free if he/she can't afford the high coaching fees and what are the strategies and tips should a student have to follow to crack jee mains and advance without coaching.....?

Hello aspirant!

Keep a copy of the JEE syllabus (https://byjus.com/jee/jee-syllabus/) at hand. More significantly, you should read the syllabus thoroughly and it will help you gain valuable insights into the important chapters, topics, marking scheme, course objectives and more. Furthermore, getting a complete overview of the syllabus will help you to develop a well-defined preparation strategy for the exam.

Reading NCERT books is also a great way to start preparing for the exam. Once you are through with that, you can use reference books and question banks.

For physics;

For chemistry;

For mathematics;

Check out these books, see what works best for you and stick to one and learn it thoroughly. Do not have too much to study from, keep your material concise. You can also use youtube as a tool - Unacademy, Khan academy, vedantu jee, physicswallah etc. One of the most effective ways to develop adept problem solving and time management skills is by practicing tackling questions from the JEE paper (https://byjus.com/jee/jee-main-question-paper/) whether it is a sample paper, previous year question paper or exercises from the books. You can also attempt the JEE mock tests to get a better idea of the exam pattern, examination mode, duration, and marking scheme. All these will help you identify your weak areas and know what to expect in the exam. In essence, you can prepare accordingly. Once you are through with a chapter, revise it thoroughly but don’t spend more than 2-3 hours on the revision. Amplify your revision by solving practice questions on the topic from reference books instead.

Make sure to understand all the core topics clearly and avoid rote learning. The questions that appear in JEE Main or JEE Advanced are designed to test your knowledge along with your analytical skills.

Along with good preparation, have a positive mindset and be confident to face the exam.  All in all, if you follow these given tips you will be able to crack IIT JEE without any coaching.