Dear Friend,

The most important thing at this stage is to believe that you can crack the exam with whatever time you have at your disposal. 

The other important thing is to remain focussed, draw a clear cut strategy and execute the plan which you have drawn to crcak the JEE Main entrance exam.

Finish the complete syllbaus at the earliest for all the three subjects.  Go through the past years question papers and get an idea which are the most important as well as mark fetching topics.These are those topics which cannot be ignored.

Once you have completed the syllbaus completely start revising.  After that start taking mock tests and solve the question papers of the past years as well as the sample papers.

Try yo prepare for the exam even when your board exams are in progress. Once your board exams are over (in case they are not falling in between the JEE Main exam), focus on revision.

With faith in yourself and right planning and execution, you should be able to clear the JEE Main exam.

I wish you all the best.