You can follow below points for your preparation-

Choose Proper Study Material:

It is a common misconception among aspirants that preparing from a number of books will help them in getting good marks. The truth is that referring the right books only will aid you in securing high. Don’t run behind multiple study material to prepare for exam.Students should choose books that cover entire Syllabus and are as per JEE and MHT-CET Pattern. Suggesting the books for preparation of Mathematics. Complete Mathematics by McGraw Hill Education Pvt Ltd., Coordinate Geometry by S.L. Loney and 103 Trigonometry Problems by Titu Andreescu & Zuming Feng are some of the good books that aspirants can refer.

Prepare a Time Table:

You should make your own time-table. So, that you can complete your syllabus on time and you get time for your revision.

Strengthen Important & Key Concepts:

Students should know that not all topics carry equal weightage of marks. Some topics carry more marks, while others don’t. Devoting much of your time on such important topics is recommended. You just need to identify such topics and practice them more.

More important topics subject wise are as follows:

Physics: Newton’s Laws of Motion, Work Energy Power, Conservation Laws, Rotation Motion, Electrostatics, EMI, Heat and Thermodynamics, Nuclear Physics and Radio Activity, Semiconductor

Chemistry: Redox Reactions, Electro chemistry, Chemical Kinetics, GOC, P Block Elements

Mathematics: Conic Section, P&C, Probability, Quadratic Equation, Definite Integration, Differential Equation, Vector and 3D, Complex Number

Time Management:

Performing well in the entrance exam depends largely on strategizing the flow and proper time management. You should decide well in advance how much time you are going to give on each subject, based on your strong and weak points. With proper time management, you will surely save yourself from the panic during the actual exam.

Solve Previous Year Papers

Solving previous year papers is the most important and required thing to do if you want to excel your exam. Itwill provide you an insight into the type of questions, marking scheme and time duration. Solving these model papers will give you an idea about how the actual entrance exam will be.

First of all, dont worry you still have enough time. Also, it is not necessary to join the coaching as there are many students who have cracked the Engineering entrances through self study only so if they can then why cant you?

So I am assuming all your basics are clear and strong so you can consider below preparation tips which will be helpful for you -

1. Know the syllabus very well.
2. Read standard books only once you are done with NCERT/state board books as there are many books available in the market so it is advisable to use the books which make all your concepts clear and which are easy to understand.
3. Understand the weightage of topics properly.
4. Proper Revision plan should be followed.
5. Mock Tests and Practice Tests should be done as this will help you to learn time management skills and this will also make you familiar with the exam pattern.

Hope this helps!!!