Colleges in West Bengal

Hi Nazrana! Here is the link:
http://www.iitkgp.ac.in/phd
Visit this link.
Best of luck.

After getting your 12th result, you can apply for this course.

Overall INIFD has a little lower rank in terms of studies and placements as compared to other fashion colleges. But saying about specifically INIFD Mumbai campus, it has a little good reputation. As per opportunities, placement level is 50-60%. So, half class is expected to be placed.
That means, in

No, mathematics is not compulsory for B.Sc in geography. You can apply via your own certificate and subjects with which you have passed your last exam. Just prepare for the test.
Best of luck.

Techno India University offers a graduation course in computer application BCA (Hons.) of 3 years duration. A student can pursue this course after passing his/her class XII board examination.

Yes, you can apply for MA in sociology if you have studied sociology previously as an optional subject.
Best of luck.

GD: Case Study
WAT: In relation with the GD Topic.
PI: Normal HR Questions, Domain Questions (Relating to your Bachelors), GK Questions, Current Affairs, etc.
PI is a bit difficult.

University of Calcutta is very strict in marking scheme. Getting 70%+ is a bit difficult in University of Calcutta.
However, if a student studies properly then getting 60% will not be a big problem.

The conversion depends on your CAT %ile, work experience, GD PI WAT performances, academics, extra-curricular activities, etc.
A CAT score of 80%ile with decent GD PI WAT can help you to convert.