Taking a drop or not totally depends on your aim. If you are determined to take admission in IITs only then you can take a drop or else you can utilize your year.

There are many good colleges in which you can consider your admission if you don't get into IITs or top NITs like BITS, VITEEE, SRMJEE and Amrita as they provide good placements.

Your options should be open appear for as many as entrance exam but make sure you take admission in one of the top colleges for engineering.

There are many companies as well which consider your gap at the time of placements. So, make sure if you drop a year make it count.

All the Best!!