MRO denying Family member certificate to wife stating non locals

Hi Sir, 10 Months back my father in law expired. He was working as Govt Teacher in telangana. Now, my mother in law has applied for Family Member Certificate in MRO office Huzurabad. She has produced all the documents like Aadhar card, Ration card, Voter Id etc. These documets are all issued in Huzurabad itself. She doesn't have Marraige certificate. Basically My Mother in law and father in law were born in AndharaPradesh, but settled and living in Huzurabad Karimnagar dist since more than 16 years. MRO is denying the Family member Certificate clammining that you are non locals and we can't give the Family Certificate here. Also, he questions my mother in law, what if there is another family in Andhra Pradesh and he is not at all cooperative. Kindly, suggest with regards to this matter. Thanks in Advance!