Hi,

See we cannot judge the cutoff of any exam which varries every year. Also about your drop query i want to suggest if you are too studious student and you are damm confirm that yea in this one year i'll sit and study all time and prepare well then it will be good to drop one year. But normally what happens is after some months students looses intrest in studying whole day. They started feeling bored or self motivation went or due to some reason that preparation thing don't happen like hoe it should had to. So you sit think and take you decision wisely.

Good luck