Hey,

If you fail in Biology theory, overall you will be considered as fail in that subject, For admission into the Bachelors of Pharmacy course, you need to have 50% aggregate in English, Physics, Chemistry, Biology/Mathematics. If you have Mathematics also, then, you can consider admission into B.Pharmacy, otherwise you need to reappear for the written theory exam.

Know more about B.Pharm over here: https://www.careers360.com/courses/b-pharma-bachelor-of-pharmacy