Hello Himanshu, 

This is the thought of every jee aspirant who ruins his exam due to some of the other reasons.

I would say you to first realize the mistakes that you committed this year which led to the ruining of your exam. Prepare a list of those, and self-introspect whether they could have been omitted, or not. You need full confidence to crack jee before you consider taking a drop. If you drop one year obviously the pressure on you will be 10 times more. As if you failed now, you will be having no choice. So think accordingly. But if you are determined, that yes, I will surely crack any NIT, and get 200+marks after dropping one year then, you should surely give a chance so that in future you don' t think that had a given a chance, I would have been somewhere else. 

I would suggest you to first focus on other entrance exams that you might have filled such as VITEEE, BITSAT or state university. Remember BITS is far better than what JEE main would fetch you. So according to my getting admitted to some of these private or government state university would be a better choice than dropping one year, and risking your one year.

At last, I would say, if it is your dream, to study in India's top elite colleges, NIT and IITs go for drop and start putting your heart and soul, to achieve your dream. But if you have 1%doubt, that you won't be able to qualify, then don't drop and opt for other methods.