please tell me what or how to study per day to do well in board exams as well as in jee ?

@ manas 
Both of them are completely diffrent examination . in one side , board which test how you represent your answer in the sheet , and JEE which test how speed u can solve the problems . 
so, u need to be efficient enough to crack the both . 
frst of all , study the ncert twice , thats the keyword i can say . once in your school , and once in your home , 
in school focus with full attention so, that yopur 50 percent of the preparation will be over their . 
and in jee also , by reading ncert u can ace chemistry , there is no problem in that . and after that , study for jee in home , and focus on imp question of board , 
beacuse in board the ques will repeat everytime and if u will practice the last 6 year paper , u can get 60 percent easily , rest percent depend on your study . 
so, take the last 29 years jee question paper , there are some books which fran=gment it chapterwise . 
so, side by side , when u study 1 chap in school , start doing the jee question . 
in this way , u can able to crack jee mains , but advanced i cannot say , as it req lot of hard work . 
and REMEMBER , BEFORE 1.5 MONTHS OF BOARD , donot touch anythng of jee level , only focus upon board . 
and once your board over , in that 1 week duration , maintain the calmness and practice at least 10 sample paper of jee level . 
ALL THE BEST ./.