CAT

Congratulations for your score.
Yes, definitely you should go for CAT, XAT and CMAT.
They provide admission opportunities in India's best B-School like IIM-A, B or C, XLRI, Jamnalal Bajaj and SIMSREE.

You will have two gap years if you have not done any job between 2016 and start of MBA course in 2018. Two years gap year will not impact your job prospects if you do well in MBA and personal interview during the campus placement. Any recruiter will condone two years gap for a good candidate.

You have to write either CAT or MAT in order to get admission in NITW. Admission will be based on the marks scored in CAT, MAT followed by group discussion and personal interview.

You may refer to following link to have an idea about IIMC PGP GDPI cut off for batch 2017-19: https://www.iimcal.ac.in/programs/pgp/admission/admission-policy/admission-procedure-for-domestic-candidates.

The pre-final/final year is a good time to appear for CAT. Pre-final year because by the time you will graduate, you will get the confirmation on your admission. If you are unable to clear the exam in the pre-final then you can attempt again in the final year and as you already have taken it once, you have a good chance to score good marks. If you are not able to make in these two attempts then attempt CAT after gaining the work experience of 1-2 years.

Dear Anubhav,
CAT is not all just about theoretical concepts. In fact, it is all about your analytical, reasoning and broadly mathematical skills. I think you must have a look at some past CAT exam question papers to understand what I am trying to say. You are saying that you are good in theory (that's good but not enough) try to improve your maths question solving ability. Your comprehensive and responsive approach should be efficient enough to crack CAT (or any management entrance exam) with good marks.
kindly upvote the answer if you feel satisfied.
Ask any query at anytime.
Good luck.

Admissions forms are available from 1st October. Please refer below links for more details:
https://christuniversity.in/2017-admissions
https://christuniversity.in/master-of-business-administration-mba/institute-of-management-mba/master-of-business-administration-mba/681

These exams are for MBA or you can say for Master's degree. If you want to do Master's degree further then you have to prepare well for these exams.

There is definitely a chance. If you perform well in CAT, you can get admission in IIMs. For this, you need to score above 97 percentile in CAT exam.

Nothing is difficult if you really want it. CAT is a little bit difficult but not that much and level of CAT in every section is very high (especially in English). So, you have to do advanced preparation for the same.