Engineering Entrance Exam

Many students at IIT have taken a drop. It's nothing uncommon, and is very normal.
I, myself, have taken a drop of one year to prepare for JEE and I too had faced this same dilemma few years back.
Also, be motivated throughout the year and try not to lose focus. The pressure on you to perform is greater when you take a drop, don't succumb to it, rather use it to your advantage.
I would advise you to make your decision free from any bias from people around you, be it your relatives or even parents, if you really have the drive to go for a drop then don't let anyone stop you.
Meanwhile if you aren't sure of yourself then not taking a drop would be a better idea. I am not saying you should have high scores this year (2017 advanced) for you to drop but should have that inner feeling that you will qualify next time no matter what. If you feel that way then by all mean opt for a drop.
Best of luck.