Science

Though you have got good rank in ST category, you will get admissions. You may have to compromise with the branch or courses. Or, you can go till the end of counseling for getting your selected course, where you can get and you shall get. Please specify which course you want to pursue in BHU.

I think, you better ask in the book store if any specific book is available for RIE CEE. For B.Ed entrance, a Rainbow Publication Book is available namely Regional College of Education entrance guide. It has reasoning, English proficiency and teaching aptitude questions. I am not sure but that may help for B.Sc. B.Ed too.

There are various career options like Agricultural Engineer. Many people don't think of farming as being sophisticated but there are so many aspiring career options such as:
Animal Scientist.
Biochemist and Biophysicist.
Biomedical Engineer.
Epidemiologist.
Food Scientist and Technologist.
Microbiologist.
Soil and Plant Scientist.

You and me, both know that 46% are very less marks. If you want job, then go through general competitions and if you want to study further, you can do some foreign language course available in different colleges and universities.