IIT

The Joint Entrance Examination (Advanced) is a common admission test for students seeking admission to undergraduate programmes of all IITs and ISM Dhanbad. To be eligible to write JEE Advanced the candidates have to first appear in the JEE Main conducted by JEE Apex Board, in the month of April.

The tentative qualifying marks for GEN category (common rank list) students is 89.75 for GEN (EWS category) is 78.21, for OBC-NCL is 74.31, for SC is 54, 44 for ST & 0.11371730 for PWD candidates.

https://www.shiksha.com/b-tech/jee-main-exam-cutoff
here is the list of the top excepted cut-off of the colleges, you can refer the link

https://www.shiksha.com/b-tech/jee-main-exam-cutoff
Here is the link you can refer to check all the excepted cut-off for IIT's and other colleges.

If you are able to pass all the trials, you can move up to the university level or even more than that it all depends upon your performance.

More than 252 companies registered students for the 2018-2019 placement drive. Almost 261 offers yielded for 428 students. The placement drive witnessed almost 22 international offers. Top recruiters include Mercari, Toyota Research Institute Advanced Development, Works Application, and SMS Data Tech. For senior batch, placements were good as compared to previous batches in terms of the number of companies and packages
you can join this IIT in terms of the placement

https://www.shiksha.com/design/uceed-college-predictor
I will suggest you to use this tool for good prediction according to your score range.

IIT Kharagpur
IIT Madras.

No there is no need of any personal interview to get admission in any IIT
https://www.shiksha.com/college/iit-kharagpur-indian-institute-of-technology-iitkgp-2999/admission
Here is the complete admission process which you refer to get admission in this college.

It depend upon your interset, if you wish to join IIT or NIT, then you can prepare well for it and can give exam in next year. Kindly join Mock test series for revision.