Hello  buddy,  now very few days left for jee  main exam. The only thing you can do is go through  previous  year question  papers,  practice  the very important  topics  of exam.  Focus on your very strong subject in which  you can score  better. 

Work hard and achieve what you want.  Best of luck for your exam buddy. 

To score good marks in your exam it is very important that You should have your basics strong. Take NCERT help to work on your concepts. It is very important to solve all the exercise given in NCERT book you can also go for NCERT exemplar.
Practice makes lot of difference specially in mathematics. Try to give extra attention to important topics which carries more weight-age in the exam. You can also solve MCQs. Solving complete mock test series is very important make sure you do proper analysis. So, that you can improve your performance. It will help you to know where you stand among other competitors. Try to increase your speed as well.

Good Luck!