Hello,


The answer to this is very simple...You need to study and that its.Give as much time as much as you can in studies and yes you will have you have to manage timing and what topic you want to study. Work on your weak areas and try to make it strong.
Limit meeting friends and spending time on social media and stay away from distractions.

Goodluck

hiii

Keep on practising. Study NCERT thoroughly. Go through every bit of the chapter. Prepare questions from inbetween the chapter. practice the sample papers as much as you can and solve previous year papers.
Make sure you know each and every formula, fact and diagram by heart.
Write a neat paper without mistakes. 
Be confident, dedicated and honest towards your studies. Stay focused and keep in mind what you want.
Do not stress out, be calm and patient, take rest along with studies to keep yourself active and fresh. Do not stay awake till late night.
Practice, Practice, Practice!!!!!!
And remember hardwork never fails.

ALL THE BEST