MBA/PGDM

You can, please check website iikm.in & contact the campuses for admission details.

To do MBA, you first need graduation compulsory. If you have graduation with work experience, you have more chances to get selected.

No need to take maths. Anyone can do MBA in finance. You should score more than 50% in your graduation.

Hello Shailesh,
If you are really interested in making a career in the HR sector, then yes it's a good choice to pursue MBA (HR). However, you have to provide a proper answer to the interviewers in case they ask you the reason to switch to HR field from CS.
Coming to the second part of your question, it depends upon the B-School you're aiming for. A score of 99+ percentile is a must for the old IIMs, 96+ for the new ones and some top non-IIMs and 85-90+ for the other decent B-Schools. Wish you all the best for your CAT preparation!

Hello Harish! It is impossible to get admission into an MBA college this year as the academic session of all the top colleges has already started from June-July. So you have to wait until next year. https://www.shiksha.com/mba/ranking/top-mba-colleges-in-bangalore/2-2-0-278-0 Kindly visit this link to know about the top B-schools in Bangalore.

Hello Sarath,
Samhbram college isn't good for pursuing MBA at all as it doesn't rank under the top 50 B-Schools in India. It would be better to simply avoid it and aim for reputed colleges.
P.S. I've myself heard the name of this college for the first time ever.