Will college admissions be open for B.Sc. courses until after the NEET 2020 exams and results are declared?

Hello aspirant. You have not mentioned the part of the country you hail from. T
Talking about Mumbai University. They have started the procedure for undergraduate programmes and shall be ending on 4th of August.
Please check with the university you are interested in asap.
From experience as well, admission to B.sc. start before NEET. A seat once taken in B.sc. can be left if NEET score fetches you a desired seat.
It's a good back up option as well.
Hope this helped with your query.
All the best.
Hope you get what you desire.