CBSE 12th

Outside West Bengal, you should try for BHU, DU, etc.

Hello there, undergraduate courses are offered by Harvard college of Harvard university. All applications must be made via Common Application. To be eligible for admission you must take SAT subject test or ACT and also TOEFL. But Harvard is also one of the top most universities, hence you must not only exceed in your academics but also your extracurriculars. Go through this link
https://college.harvard.edu/admissions/application-requirements
Hope this was helpful.

You can apply for
microbiology
anthropology
botany
zoology
environmental studies
If you have maths then the horizon widens and you can pursue
pure sciences. Good luck.

You can pursue foodtech from applied Science colleges, architecture, law and BBS.

If you want to go for Diploma its better to do after 10th as Diploma has 3 years and nowadays it has become necessary to go for degree too after Diploma so if you later wish to go for a degree programme then it would just elongate the years if you do Diploma after 12th.

Dear aspirant,
You have a fair chance of getting a call. Fill the application form.

There is no tip just don't miss use the time as man can't live without water in the same way the study finds uncompleted by itself you can't each time to your study sorry to understand point.