Hello, the exam syllabus for NEET is of 11th and 12th standard level so it is not necessary to have pursued a higher studies in biology field though it offers an advantage to only some extent. The syllabus during your 1st year BSc Biology will cover extended topics from your 12th board implying that you should be already strong in basics. If you thought you will have a revision of chapters it would be only for a meagre amount of the syllabus alone.

You can refer this link on more details on NEET 2021 https://medicine.careers360.com/exams/neet

Best wishes.