CAT

Don't count your chicken before they are hatched. First, concentrate on giving your best in CAT. You will get ample time to choose your college after getting selected.

Usually, study materials provided by T.I.M.E and Career Launcher are good enough to study for CAT exam as they are updated regularly based on a change in CAT exam pattern. But for this, you have to take admission in these institutions. But if you are not interested to join, you can go for NCERT books, R.S. Agarwal and Arun Sharma. You can purchase them at book stores and even online.

IIMs have more than 99.5 percentile as their cut-off. Depends on college to college.

Don't worry. You will do well. Prepare well for CAT.

Hi Manoj,
It is really tough for you to get a call from IIT Roorkee for this percentile.

Hi Prashant,
It is not possible to get a call for this percentile.

Hi Prashant,
For an SC candidate, you have to score more than 70 percentile to get a sure shot call from IIT-Roorkee. But it is possible if your profile is good and percentile is above 65 you get a call but then you have to perform well in an interview to convert your call.

You can find the previous year's cutoff details here: http://www.iimrohtak.ac.in/addmission/wat-pi-2015.html .
Yes, there are a fair number of students from commerce background, in fact, I am one myself.

The rank is just quite ok, but according to the cut offs it seems quite difficult, but anyways you can try till second session of counselling. Hope for the best.
The teaching faculty is very nice. You feel very much comfortable with the learning experience there.