CMAT

Well, good colleges will always have cutoffs mentioned for the courses. So, if you have cleared the cutoff, you can definitely apply. As for the OBC Category, it applies to only MBA and MHRM, as it comes under the University. PGDM is autonomous, that is it is run by the college itself without any assistance from the University. So, OBC reservation will not apply for PGDM.

Yes, actually. But, remember, any student who has cleared the cutoff can actually apply to Rajagiri Business School. So, you can apply, but students who have scored more than you will have an upper hand. Doesn't mean that you won't get the admission but just saying those students have more chances. According to my experience they will most probably call you for an interview. If they do, do well. All the best.

Yes, you do hold a chance to get admission in Chetana's Institute of Management and Research through PGDM if you do well in your GD and PI process.
You will have to enrol for the admission process, the last date for which is March 31.

Your score is bit low. You are eligible for the tier 3 colleges. But, you not be able to get seat in top B-Schools in tier 1-2 colleges. You might get seat in colleges like D Y Patil, ISB&M, IBMR etc. But, for colleges like WELINGKAR, KJ Somaiya, BIMM, Christ University and other colleges of Bangalore and Maharashtra you need above 80 percentile. Further, you can also try for paid seat in top B School in India.

What if someone has scored 243 marks and belongs to OBC category?

The eligibility criteria of IFIM Business, Bengaluru is as under:-
Candidates are required to have a bachelors degree from a recognized university with a minimum aggregate of 50% for all subjects taken together (45% for SC/ST candidates).
Acceptable test scores :- Must have qualified in one of the national level management entrance examinations, viz., CAT, XAT, or GMAT.
Hence, MAT and CMAT are not acceptable here.

Yes, you do hold a chance to get admission in Chetana's Institute of Management and Research for PGDM if you do well in your GD and PI process.
You will have to enroll for the admission process, the last date for which is March 31, 2019.