CAT

You have a thin chance because cut-off for HRM is to be expected High this time. You have a good academic record so what you do is fill the form with two dicipline with HRM as first option and try your luck.

You'll get a call.
Since the investment is comparatively much less than what you need to do in other colleges, the return is good enough. However getting placed is completely upto your own calibre.

Satabdi,
Sectional cut off depends on college to college. Some colleges have sectional cut off some don't. You need to check with the colleges for the same.

Yes you can go for KMAT after completing your graduation.
Eligibility for KMAT:
Candidates need to have Bachelors degree / Masters degree from any recognized education body in Commerce, Management, Arts, Social Sciences, Engineering / Technology or equivalent
Atleast 50% aggregate marks; 40% for SC/ST candidate
Candidates will then be shortlisted on the basis on their performance in KMAT. The scorecards of the candidates will be sent to the colleges.
The selected candidates who have qualified in KMAT need to report to their respective college to secure admissions.

Some of the colleges are:
New Delhi Institute of Management, NDIM, Tughlakabad, Delhi
Xavier Institute of Management and Entrepreneurship, (XIME Bangalore)
Asian Business School (ABS, Noida)
Indus Business Academy
Jagannath International Management School
Indus Business Academy (IBA Bangalore)
Christ University Institute of Management, Hosur Road, Bangalore

As you are not willing to drop this year then you can go for these colleges:
New Delhi Institute of Management, NDIM, Tughlakabad, Delhi
Institute of Technology and Science (ITS), Ghaziabad
JK Business School (JKBS), Gurgaon
G.L. Bajaj Institute of Management and Research (GLBIMR), Greater Noida
Institute of Advanced Management & Research(IAMR), Ghaziabad

The chances are meagre. However you might get a call if the overall results in this year is low.