To become a MRO, you should appear for Andhra Pradesh Public Service Commission Group 2 exams. If you were born in AP and are a bonafide citizen of Andhra Pradesh, then studying your Graduation in Karnataka should not disturb your domicile and so you will be eligible for Group 2 exams. But if you have been born in Karnataka, studied your 12th in AP and moved back t Karnataka for your Graduation, then you cannot apply for APPSC Group 2 exams. To hold the domicile of AP, you should have resided in the State for atleast 7 years. If you fulfil this criteria, then you can appear for APPSC Group 2 exam and should you qualify in Group 2, you can take your job as a MRO.