Dipa, a score of 300 is less if you belong to General Category more even if your specification are confined to Government Colleges. Though NEET is the entrance examination for admission to Medical, Dental, Ayush and Veterinary courses, because you belong to General Category, the cut offs are usually higher than 4500-500. So if you want to study any of the Medical, Dental, Ayush and Veterinary courses, you may have to reappear for NEET 2021. If you want to prepare for NEET 2021, we do have a Knockout package: https://learn.careers360.com/knockout-neet-may/

Dear Aspirant
At first lots of congratulations for your result and wishes for your future life. Since you mentioned your expected marks 300+ , I am assuming it around 300 as you have not mentioned your maximum expected marks.  I am afraid to inform you that with your score your chances in All India counselling are almost negative for the 15% seats as well as for the government colleges in state counselling for 85% seats .However you can get good private colleges in West Bengal. They are
SHRI RAMKRISHNA INSTITUTE OF MEDICAL SCIENCES AND SANAKA HOSPITALSICARE INSTITUTE OF MEDICAL SCIENCE AND RESEARCH AND DR BC ROY HOSPITAL HALDIAI Q CITY MEDICAL COLLEGE, Durgapur
KPC MEDICAL COLLEGE AND HOSPITAL, JADAVPUR
ESIC Medical College, Joka, Kolkata

check your chances in varius medical colleges here
https://medicine.careers360.com/articles/neet-cutoff-west-bengal/amp
prodict your NEET counselling chances here
https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer

Best Wishes.