Hello aspirant,

You have good chance of getting a government dental college with 520 marks. Here is a list of colleges with previous year cut off rank-

1. Government Dental College RIMS, Kadapa- 156257

2. Burdwan Dental College and Hospital-  84699

3. Goa Dental College- 160912

4. Government College of Dentistry, Indore- 160119

However, it is difficulty to get into dental colleges of UP with 520 marks according to the previous year cut off.

You can also the college predictor tool to help you analyse the colleges you can get into- https://medicine.careers360.com/neet-college-predictor

Hope it helps!