Sir, how to manage time if I am dropping an year? what should be the ratio of hours of study and breaks? And how often should I take a break? Sir, please answer as soon as possible..

@ muskan 
mention for which exams u are talking about – JEE or NEET . 
if jee , then u need to focus more on numericals and target should be like this – u need to complete the syllabus once and then stress upon those chapter in which u are weak and commited mistake last year . 
so, the no of study hours and break will depend upon you as we cannot define any minimum criteria for the study plan , but u need to cover 3 subject per day , thats it . 
u can takle break after every 1 hrs of study , else brain will not work properly . 
ALL THE BEST ..