I have a month for my jeeand also my CBSE board can you please tell me how many hours should I sleep and prepare for my new my and board

dear prasi 
its a difficult time for you . 
so, you need to manage time for both . 
so, donot ignore sleep , thats very much required now . and now , only focus on board as its very imp , beacuse ypou have only 1 chance for board . 
so, make your boards first priority . 
then after the main subject gets over ( P,C,M ) , you need to start revising the 11^th syllabus , just by revision notes and some good ques . 
but make sure not to forget 12^th concepts /. 
regards