Brother expired without writing a will. How to divide his self acquired proerty?

I, C.Sridhara, aged 74 years, residing in Bangalore, would like to bring the following lines for your kind attention and request your guidance. My brother, C.Shashidara ,when he was 67 years old, without writing a will, expired 4 years back , at Mysuru. His wife was not staying with him for more than 30 years and divorce was not permitted and they do not have any children. His mother, aged 94 years, was staying with him till his death. In death certificate, name of wife of my brother is not there. My brother's wife's Aadhar card, in the address it is indicated 'Care of Shashidhara" but not "Wife of Shashidhara". The only proof she has is the divorce papers to prove that she was Shashidhara's wife. My brother was having a self acquired property at Mysuru. So it is decided to divided the property between the mother and my brother's wife. So 'Vamshavruksha - 'Letter of surviving family members of the deceased' is obtained and submitted to Mysore City Corporation . But Mysore City Corporation insisted that 'vamshavrukasha' has to include the names of Mother, her daughter-in-law and the deceased only is required, but the obtained 'vamshavrukasha' includes the names of mother, wife, brothers and sister of the deceased. But application for required 'vamshavrukasha' is rejected as brother and sister are existing. Tried through some advocates several times. Nothing worked. Kindly suggest me the suitable procedure so that a joint Khata is obtained in the name of my Mother and Brother's wife. OR Khata to be obtained by my mother's name and later 50% of the share to be transferred to my brother's wife. Thanking you -C.Sridhara