Engineering Entrance Exam

Please check the link provided for complete details about the college by your marks, rank, category and branch of interest.
https://www.shiksha.com/b-tech/resources/wbjee-college-predictor

Yes, the ranks for JEE main and that of JEE Advanced will remain the same for JoSAA counselling. You need to choose your category and then you should see you rank.
The link below gives you the previous year closing and opening ranks for each NIT, IIT, IIIT and GFTI:
http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx
You select your category and then the type of institute then you can see the data for 2016. The official closing and opening ranks for this year have not been released.

Chances are less for getting admission in ECE at Institute of Technology, Nirma University, Ahmedabad. But you can try for it and yes, of course, it will give you a very good career.

No, you should have more than 75% marks in class 12th boards or you should be in top 20 percentile.

You can check the opening and closing rank for general category by doing some Google Search. I think you have less chances but don't lose your hope and hope for the best.

There are total 2 attempts to appear for BITSAT. So if you have missed then you can only appear in 2018.

Hello Vishnu,
Your marks are too low to get any branch in any government colleges, so look forward for colleges via other examinations. However, check here for more insights.
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

It is not easy to get MITS B.Arch in 20000 rank. You should apply for counselling I think you should get.

DAIICT and Nirma University are the best amongst the all and amongst these 2, DAIICT has no competition.

Negative aspect are many and positive aspect came if you qualified IIT JEE this year as if you drop for your 3rd chance so there is lot of pressure on you that I had dropped this year also so atleast I got NITs so you prepare according to then and if you dropped then there is also a pressure from your parents and society. this 3rd drop is also questioned by company when you go for campus selection.
Overall conclusion is I don't know your this year JEE marks but according to my experience if you got 100+ this year and wants IITs or NITs then only think about taking chance this year also.