Legal Heir Certificate

Hi My dad expired in 2013 in Bangalore due to natural cause and the death certificate was issued with both Present and Permanent address pointing to the address (in JP Nagar) where I stayed. However, we hail from Tamilnadu and some of his assets are there. Moreover, there are few other things like Gas connections and bank accounts that were not transferred or nominated. He' not written any will as well. My brother, who stays in Tamilnadu, was trying to change the gas connection in his name for a while now but the death certificate was outright rejected saying the address is pointing to Karnataka and doesnt hold good. He' been informed that a legal heir certificate should be obtained to prove he' a legal heir. Now I've couple of questions: 1. Should we be getting the legal heir certificate in Bangalore as the death certificate is issued here? Or can we file for the same in Tamilnadu? We were told its the former option we should choose. 2. If I've to file for one in Bangalore, what is the procedure? whom should I approach? and where should I apply? I currently stay in Whitefield area.