IIT Kanpur - Indian Institute of Technology

Information of this sort would be available on the website.
Link: http://www.iitk.ac.in/.
However it is likely to change every year but the changes would not be drastic.

For general category students, all those with 92 percentile and above were called for interviews and out which students have been selected on the basis of their cumulative scores for CAT and GD-PI.

Admission in B.Tech CSE at IITs is by appearing in JEE Mains and JEE Advanced. The upper age limit to be eligible for JEE Main is 25. Age limit is relaxed by five years for SC, ST, PwD candidates.

No, only engineers or M.Sc Maths.

Yes, in India CSE has a huge market demand.

You can earn more than 15 LPA.

No, both are different course and have different admission criteria you need to appear and compete through JEE in order to get admission in any B
Tech program and teaching method, as well as pedagogy, is different for these two programs. You may opt M.Sc and if allowed M.Tech after M.Sc.