Engineering Entrance Exam

There are success and failure stories of JEE with or without external support. The choice of going for self-preparations or coaching for JEE depends upon your personality, intelligence level and budget. If you are self-determined student with high IQ, who is focused and capable of achieving targets

Dropping a year means that you will get sufficient amount of time to prepare for competitive exams. It will allow you take mock up test and help to score good ranking in competitive exams. However, one year is a long time, so the possibility of you may change your goals and objectives.
You may become

The counselling is in the month of July or August.

No, as the pattern is changed, but formulas and concept is same.

A candidate can attempt JEE Advanced, a maximum of two times in consecutive years. Therefore, candidates who have appeared in JEE Advance 2016 for the first time are also eligible.

Yes, you can take chance in JEE Mains.

Hello Piyush,
You have stated that you have completed class 12th in 2015. Those who have completed class 12th in 2015 or earlier are not eligible.

It depends on you. If you want to be a part of IIT, then you need proper guidance and study materials. I would advise you to join IIT-JEE coaching, where they will show you right path to crack the entrance of IIT.

The best private colleges conducts their own entrance exam for admission, but there are still many colleges, where you try through JEE Mains. If you have good marks, then they will provide you scholarship.

It is quite difficult to predict the rank. You can use colleges and rank predictor apps for reference purposes.