Hey there

As far as I understood you have not prepared anything for your JEE till now so in that case I suggest you that you have 1 year left (almost) you can easily devote 4-5 hours honestly to chemistry which if you complete then it will give you atleast 70 which is a good score now in physics your 12th portion is a must and in 11th do rotation, waves, work power energy chapters and in maths it is compulsory that you devote 4-5 hours daily to this subject otherwise you won't understand anything. Keep in mind that if you want to get 180 you will have to put a lots of efforts on a regular basis irregularities always results bad. 

Good luck