B.Sc

I do not have knowledge about this. You can search it on amity. Edu and can contact the university personally as well.

It depends on your interest. So, if your interest is in software field, then you should go for either B.Sc in computer Science or BCA.

B.Tech and B.Sc both fields are good in their own way. It depends that in which field you are interested in. I would suggest you to go with B.Sc in perfusion technology, if you have interest in the equipment.
The Perfusionist is in charge of operating these machines with the heart-lung machine being the most commonly used one. The machine basically takes the blood and oxygenates it while the heart remains dormant during the surgery.

You can pursue M.Sc in Quantum physics, even if you haven't studied it. In your graduation, you just have to come up with the new syllabus. And, remember to cross check the same thing with the college you are trying to apply in.

B.Ed is the best field to enter the teaching field, because it is much valued in India, and if you want to do some research or complete doctorate in Science stream, then go for B.Sc and M.Sc.

You have not provided enough details in your question, but still as a suggestion I recommend you to do M.Sc after B.Sc. And, enter the teaching field by clearing CET and NET.

Please click below to check the eligibility for the same. https://www.shiksha.com/science/course/b-sc-hons-in-statistics-st-xavier-s-college-kolkata-park-street-83773.

B.Sc in Perfusion Technology Eligibility criteria is:
The candidate must have cleared 10+2 or any equivalent examination from a recognized board under the Science stream with compulsory subjects Physics, Chemistry, Biology (Zoology or Mathematics) and English with 50% minimum marks. * The minimum cut-off is 45% which varies depending on the institution. There are many more career details in Best B.Sc Perfusion Technology Colleges in Bangalore.