Science

University of California, Los Angeles (UCLA). Princeton University.
Harvard University.
University California, Berkeley (UCB).
Carnegie Mellon University.
Stanford University.
Massachusetts Institute of Technology (MIT).
California Institute of Technology (Caltech)
University of Washington.

I appreciate your sense of approach. Answering your question. Changing a branch is up to you my friend (my personal opinion is to not to change the branch).
But before you opt for another branch, keep an eye on various subjects and your interests upon the subject. It's your future and your own life. So, you should be aware of your interests and take a branch according to your interest. Talking about your preparation which you did in these 3 years, it doesn't mean the struggle you had is useless. Remember, every experience gives you the new technique and new ideas. So, never lose hope and keep trying.

Kindly visit this link:
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/design/fashion-design/colleges/b-sc-colleges-Hyderabad&ved=2ahUKEwjtut2Iv6bcAhULqI8KHWuoDwQQFjAIegQIAxAB&usg=AOvVaw3xpkAbgbuwXWZHHVUHyatZ

Hi,
After doing zoology you can choose any specialisation course in genetics, biotechnology, endocrinology, immunology, applied zoology, wildlife science, ecology and you will be eligible for all these specialised courses in most of the universities. If you don't want to go for higher education, you can get jobs in government sector by clearing the exams and can sit for IAS more preferably Indian Forest Service or all State Government Forest Services. You can also crack CSIR NET (life science) or UGC NET (environment Science) or GATE (Evolution or ecology).
Thanks.

Hi,
In order to pursue hotel management you need to be pass in all the subjects in 12th standard. You can fill the form for NCHMCT JEE and simultaneously clear your compartment before admissions.

Hi,
MCA Eligibility"
Any graduate who has passed or appearing for the final year UG examination in any discipline (Science, Commerce, Arts, and Engineering) is eligible to apply. Candidates must have mathematics as a subject in their 10+2 course or any one year of graduation. If you have maths in class 12 then you can apply.
Thanks.

Hi,
For B.Sc specialisation details, you can see the below link:
https://www.shiksha.com/science/articles/amp/what-is-bsc-course-all-about-know-the-full-form-eligibility-scope-blogId-13262
Hope this information will be useful for you.
Thanks.