why are you concerned about this??????........... no. of hours you study and sleep does not matter much.............. its the amount of concentration with which you study that matters........if you sleep for say 4-5 hours than your productivity would be low and you would not be able to concentrate ........ JEE does not only requires hard work,........ it also requires smart work..............so just see that when you study, study with full concentration
best of luck...........................
why are you concerned about this??????........... no. of hours you study and sleep does not matter much.............. its the amount of concentration with which you study that matters........if you sleep for say 4-5 hours than your productivity would be low and you would not be able to concentrate ........ JEE does not only requires hard work,........ it also requires smart work..............so just see that when you study, study with full concentration
best of luck...........................