Hello, 

The score 300 is low when compared to the last year's cut off marks of the private medical colleges.  

The cut off marks for general category is more than 400 for private medical colleges. These cut off marks may increase or decrease depending upon the difficulty level of the exam, number of students appearing in the exam, etc. It is always better to have a score higher that the last year's cut off for easy admission. 

A lower score than the previous year's cut off marks usually has a lower chance of admission in MBBS or BDS courses in private medical colleges. 

Good luck.