Hello, 520 is a good score in NEET. However, getting admission in government through All India Quota will be a little difficult as the cut off marks are 600 and above. Getting admission through state wise quota will be easy as the cut off marks are in the range of 500-550. Following are some colleges with their cut off marks in the year 2018. 

1. Bangalore Medical College and research institute, cut off 512.

2. Mysore Medical College, Mysore, cut off 443. 

3. Mandya institute of medical sciences, cut off 402

4. Karnatake institute of Medical Science, hubli, cut off 455.

5. Belgaum institute of Medical Sciences, Belgaum, cut off 428.

There are many other colleges which might give admission for MBBS with a cut off of 500-520. 

Please visit the following website for more colleges and their cut off information. 

https://medicine.careers360.com/articles/neet-cutoff-karnataka

All the best.