Coimbatore

Hi,
There is a chance for you. Keep your fingers crossed, but the chance of getting scholarship keeps on changing, based on the number of candidates opted at a particular location. As per note from the campus:
Tuition fee waiver ranging from 90% to 25 % is awarded to the students, based on their rank at the time of admission counselling. Scholarship seats are earmarked in each branch in each campus. A total of 300+ candidates are eligible for scholarship at the time of admission and continuation of scholarship in subsequent years would require meeting the minimum required CGPA during subsequent years of study.

Nope, not even in your bags or else it is likely to get confiscated.

JEE Mains 2018 College Predictor:
Use your JEE Mains 2018 rank to see where you can get admission at the link provided below:
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The result is based on admissions data of JEE Mains 2017
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https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.

Yes. You can get admission for B.Tech mechanical. Polytechnic students can get direct admission in 2nd year i.e. called lateral entry or direct second year. Based on your percentage of polytechnic, you can get admission. Enquire in college directly to find out the procedure.
Good luck!