Science

B.Sc (Hons.) Physics is 3 year undergraduate course in physics. The candidates who are willing to take up this course must possess a minimum of 50% of score in their 10+2 or equivalent examinations in Science stream in a recognized board school. Admission process of this course is carried out based on the candidate's performance in their high school exams. Some institutes may also conduct their own entrance exam for admission to the course.

No!
Maths is not there in B.Sc in Environmental Science. In B.Sc in Environmental Science, subjects like Environment chemistry, Green Chemistry etc. subjects may be present.

Hi Appu,
You can pursue M.Sc in chemistry or Maths only if you had chemistry or Maths as your subjects in your graduation, only then you can pursue M.Sc. In respective subjects otherwise you are not eligible for the same.
Good luck.

Yes, you're eligible to get admissions. Just attend VITEEE and based on your rank apply for the consecutive campus.

If you score more than 85%, there are 80% chance that you might get admission in the course.
I left the 20% because there might be some chances that the seats might get filled soon depending on how many apply for that course.