Succession certificate/Vumsa Vriksha certificate

I am Ramesh. I live in Bangalore. My father A Viswanath passed away last month leaving my mother and me as the legal heirs - I am his only child and have no siblings. My dad passed away in my house in Bangalore and my family now includes my mother, my wife and my kids. He has left no Will. We have an ancestral property which is registered jointly in my dad's name and my name. This is located in Chennai where we used to live till 2009. The property is currently rented. By virtue of my father's demise I guess the 50% part of his share in the property (rest is in my name) will accrue 25% to my mother and 25% to me. My mother wants me to completely get this transfered to my name. I am told that unlike Tamilnadu where the Tasildar can give a legal heirship certificate, Karnataka does not work that way. I am given to understand that only a succession certificate and vumsa vriskha certificate needs to be obtained through a lawyer. Is this understanding right? Can you help me on this? How long will it take? What are the charges?