Dear Umesh, one of  the eligibility criteria to apply for NEET 2019 is that your highest qualification should be +2 with subjects like Physics, Chemistry, Biology/Biotechnology and English as core subjects with 50% as your qualifying marks if you fall under General Category. Now assuming that the basic eligibility for NEET 2020 remains the same, by 2020 you will be in your B. Sc Final year. If your B. Sc degree has atleast 2 subjects among Physics, Chemistry, Biology/Biotechnology, you can write NEET with your B. Sc qualification.