Hi 

This is Ritika

You are in 13th or we can 11th .11th and 12th is basic for jee exam .The pillar of scoring good marks in jee as well boards is 11th .11th is the base, concept of every chapter in 12 or jee is directly or indirectly based on 11th.

So dear if your doing preparations for jee and trying to score good marks then from today just start studying ,as no day is late ..Do regular study ,devote time on each subject equally and try to cover up the chapter,solve DPP and give regular test.

All the best

Hope My answer helped you

Thank you