It depends on several factors:

1. Your domicile State.
2. Number of Medical colleges in your state
3. Performance of students in your state.
4. Total number of seats.
5. Number of Reserved students in your state.

With 300 marks in NEET exam , you can get private medical college easily but their fees are little bit higher.

If you want to do your degree from government medical college you need to score more marks .

Caste also plays important role in getting government medical colleges.There is girl in my batch who got admitted in her first round in Shri Vasantrao Naik Government Medical College ,Yavatmal with 315 marks only . Later she upgraded to Goverment Medical College ,Nagpur in fourth round.(She belonged to ST category)

You can also get government dental college with 300 marks .