B.Sc

No, it is not. After completing B.Sc, you are free to opt for a career of your choice or opt for higher studies, whichever you deem fit.

Yes, you can definitely appear for NIFT entrance exam after completing B.Sc (Hons) in physics.

Different colleges have different admission criteria. Normally, candidates should have the following qualifications to be eligible for B.Sc.
1) Students with 50% at 10+2 level from a recognized education board with science stream can opt for B.Sc.
2) Some institutes also conduct entrance exams for admission into B.Sc.

If you have backlogs in your current course, lateral entry into another university will become difficult. Please check with the admissions department of your institute.

You should pursue a course where your interests lie. Please refer to the link mentioned below for a detailed comparison between the two:
https://ask.shiksha.com/what-is-the-difference-between-b-sc-agricultural-biotechnology-and-b-sc-general-biotechnology-qna-3056566

The career in fashion design is a long term project in one's life and it is one of the best paying industries. Some of the jobs you could explore in fashion design field are as follows:
1) Fashion Designer
2) Fashion Illustrator
3) Fashion Stylist
If your strengths lie in illustration, you should pursue a career as a fashion illustrator.

That depends on the university you are applying to. Few universities have minimum 60% as the cut-off while others have 50% as the cut-off. For eg: DU has 60% as the cut-off, whereas, Manipal has the 50% as the cut-off.

If you are interested in physics, then go ahead. Don't be confused if you can do better in physics than other subjects, then you must go for the same.

Hello Shahid,
The management school of BSAU is called Crescent School Of Business.
It offers decent placement for MBA and other business programs.
You may refer below :
http://www.csbedu.in/placements/