Hii Lavisha!

Study for 11th CBSE exams only for 4 months. After you give exams, you will have covered almost portion of class 11th.

I suggest you to make last minutes notes simultaneously.

Once the exams are over, start your 12th chapters.

In 2 months, go through all the chapters of Physics that are arriving at JEE exams.

Now, in next 2 months, do for Physics and same 2 for Chemistry.

PRO : Start solving questing, learning formulaes and making notes simultaneously.

Now, for next 2 months, solve questions of advanced level.

Read high-level books. Solve practice papers and previous year question papers.

Next one month, REPEAT NOTES

Finally, attend real time question papers so that you can understand your level of preparation and make changes accordingly.

Good luck!