Still a lot of time is left... That is enough of time to score 500+. Because at 300 marks, you cannot get government MBBS BDS colleges. Even BAMS BHMS colleges look difficult. So start making a timetable... And study more and more as much as possible and finish your 11th now also. It's not difficult trust me because if you don't have 11th basics, solving and achieving your 12th std section becomes difficult. If you have any queries regarding a particular subject or chapter, feel free to ask in the comment section.

Best wishes. Thank you.