Hello Pranav

Marks and percentile will depend upon the way you are studying and how much time you are giving to your studies .

There are some key points ; which help you to score good marks:

• Choose your guide / teacher good 
• Make a time table in which minimum 7-8 hours will be study.
• Make key point of the important points
• Donot get disturbed or frustrated 
• Donot compare yourself with other and don't see what other are doing.
• Always talk to your teachers and parents 
• Stay healthy and happy .
• Use books properly with guidance and use good books and study material
• Start with NCERT and donot jump on 2  or more books simultaneously.firstly complete the one book thoroughly
• Concepts must be read and understood thoroughly and in deep
• Numerical practice is very necessary
• Do not skip any concept ( like I will do it later or it is very long etc issues )
• And keep patience because resulta and progress will be shown after a interval of time.( So keep studying regularly)
• And practice good quality questions and packages of any good institute and take a test series

All these tips lead you towards success..

Good luck 

Hello Pranav 

It doesn't matter if you are an average student or an brilliant student, you can do well in JEE mains irrespective of that. What you need is perseverance and determination to achieve the goal. If your basics are strong then you can consider your preparation half done. With the scores you mentioned your basics seem to be weak so work on that. You can further build on the concepts and achieve your goal easily. 

Hope this helps

JEE exam preparation needs a good strategy :-

1. Good books/material:- 

           for physics- H C VERMA(for both theory/concepts and problems) 

           for maths- M L KHANNA 

           for chemistry- physical and inorganic- O P TANDON

                                     organic- SOLOMONS

Take these above all books for making basics clear at first then see NCERT BOOKS and simultaneously mark the topics that you covered through these books and  read NCERT books only at last two months.

After clearing basics you need to take a latest coaching material to solve latest problems in JEE exam ,best material is from "allen study material" you can buy it secondhand from OLX . I am not promoting anyone just i have experience of many coaching materials.   

2. Time management:- 

Many students waste their time at schools classes ,see you cant take so much leave to do self study but you can do one thing ,you should take problem sheets with you at school and can solve them in free time and also ask doubts from school teachers and your friends.

Awake early in morning like 7:30 am and sleep at 12:30pm and can take sleep of 1 hr 30 mins at around 4:30pm.

3. Choosing most interest topics:-

     choose topics with your more interest and make them strong first.

4. Set daily targets :- 

     set your daily goals but never demotivate if you fails.

5. always be self motivated

6. Never feel jealousy with your competitors