You did not mention your category. But in general you will need atleast 450-500 marks if you belong to General Category and Karnataka is your home state. If you belong to any of the reserved Categories, you will need atleast 400-425 if you belong to Karnataka. Other State students also can apply for Karnataka private colleges and so there will be tough competition. Cut offs change every year depending on few factors so you should score 400-500 for atleast management seat in any of the private medical colleges in Mysore.