Anchal, now that NEET registration has passed, the chances that NTA will reopen the registration again are null. So you have to wait until NEET 2021 if you are determined to study medicine. While that is still a year away, you need to figure out your immediate plan. Joining B.Sc is not a bad option because there are many Candidates who take a break or join some course while preparing for NEET at the same time. It is not just B.Sc but there are also a list of courses that you can pick up from which will be light on your academic schedule while you prepare for NEET 2021. Please check the list of courses that you can study after Biology in your 12th at: https://news.careers360.com/cbse-releases-list-compendium-courses-students-pursue-after-12th