CAT

To be honest, 51 percentile in any MBA entrance exam won't fetch you calls from even the average B-schools. I advise you to study hard and try cracking these exams starting later this year. A great percentile and a decent GD-PI round should fetch you admission into the choice of your B-school(s).

CAT exam enables you to fill the form of the college where CAT is mandatory. Some average colleges have MAT mandatory, otherwise, they will not allow you to fill the college form. These are mandatory only for MBA students. CAT is widely accepted all over India in all management colleges.

S. Chand's books and other similar books are good for quantitative aptitude in CAT.

You can expect a call for GD/PI considering your score.

You will get a call for GD/PI based on your scores.

Cut-off is around 70 percentile and average package is Rs 5.5 lakhs per annum.

The cutoffs for even the new and baby IIM's are above 91 percentile. With a score of 17 percentile you would be lucky to get into any college let alone good ones. Forget this year's scores and concentrate on next year.

The cut-off of admissions changes every year.
Last year, the cut-off was:
CAT - 86 percentile,
CMAT - 96 percentile and
XAT - 78 percentile.
For more information refer brochure:-
https://www.somaiya.edu/media/pdf/PGDM_Admissions_Brochure_2017-19.pdf .
Online Application Form:-
http://simsr.somaiya.edu/simsr/adm/pgdm17/onlineform/login.aspx .
FAQs:-
https://www.somaiya.edu/media/pdf/FAQ_2017-19.pdf.
Placement Report:-
https://www.somaiya.edu/media2/pdf/Placement_Report_2015-16.pdf .

You must try to get at least 85 percentile to get a chance of admission in a good college in Delhi like:
1. IMI.
2. LBS.
3. BIMTECH.
4. FORE.
5. DU.
You can appear for IIFT exam to get admission in IIFT - Delhi.