The change in the cutoff marks is not that drastic but the marks or rank differs by 30-40% and it can go higher by this amount. The change would be dependent upon the number of students appeared for the exam and the level of the exam and based on the marks obtained by the students the merit list and cutoff marks are accordingly prepared. Go through the link below to know about the cutoff marks for the karnataka state quota seats.

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