Hey there!

As you don't have the domicile of the BIhar, then you are not eligible for the 85% state quota seats, therefore you will have to apply through the 15% All india quota, usually the cut off for the All india qouta seats are higher than the state quota seats. But with your neet score of 530, given the trend in the cut offs, you do have chance of getting admission the Katihar Medical college, but again nothing can be predicted with surety.

To get better idea of government, private colleges or deemed universities you can get into, you can use the neet college predictro tool. here's the link - https://medicine.careers360.com/neet-all-india-college-predictor?icn=QnA&ici=qna_answer