Friends we all come to a point in our life when we can't see ahead because of certain extreme situation and we r confused. To move ahead in dark or to move back in search of torch. Similar is the condition when u couldn't clear jee mains and think about dropping one year and prepare again. It could be a wise decision only if you are a few marks below the cutoff and are sincerely dedicated for IIT only. Else it waste of time. Moreover there are several other good institutes for doin btech.hardwork , regularity,intelligence is what going to shape ur future not any institute. If u r goin to drop then u will push yourself 365 days back. Which could mean 365 days experience if you complete ur degree one year before. There are many students gettin good packages even from private institutes. Moreover it giants like facebook also prefer students from other institutes. So just don't get embarrassed if u r hardworkin,intelligent,innovative u don't need IIT to be written on your graduation certificate. Its all about efforts and sincerety.