Hello student, 

The cut off marks for Tamil Nadu and Karnataka under All India Quota are 550 and above. This score is for 2018.  As the cut off marks tend to increase every year there are very low chances of getting admission for MBBS in any of these states under AIQ. 

However, there are certain colleges in the state quota in the state of Karnataka which might give admission for MBBS for 497 NEET score.  For example, Mysore Medical College, Karnataka institute of Medical Sciences, Belgaum institute of medical sciences, etc. 

Good luck.