Hey Aman,

If you want to take a drop year and prepare for a better college or join any lower tier college this year is and should be entirely your decision and let no one else take this decision for you.

However, how others as well as me (here) can help you is provide you with the pros and cons of the dilemma you're undergoing.

Now, to begin with your JEE percentile might not allow you to take admission in any of the top-tier colleges.

TRUE , but unlike many other aspirants you are clear in your goals that you want to pursue a career in CSE.

Most of us prefer top tier colleges just to be around the best brains and majorly to develop a perspective in life which may not be the case with you. Also a good score in JEE will not get you anywhere in life other than a good college, wherein also, your efforts will build your future.

Also, I would like to add, in the software industry your skills are given more preference to the college you've done your graduation from and it often happens that students from a lower tier college ends up getting more paid.

This being said, it is also true, that a top tier college gives you peers being around whom helps you develop and hone your skills in a symbiotic manner and this makes you a better person in life. Not to forget the alumni network you become a part of, might also come in handy in several occasions.

Also resume shortlisting may have some effect over others (belonging from a lower tier college), but do remember its your skills that you develop in these 4 years or over time that will take you further in life.

Now, its entirely your decision what you want to do. You know yourself better than anyone else and therefore do retrospect and come out with the most logical decision you feel is correct.

All the best :)