Please help with my Fixed Deposit Issue

Good Evening, My father had quite a number of Fixed deposits in an NBFC called Tamilnadu PowerFinance, all of which were solely earned by him. The deposits were opened in His name and His mother's name, with his Mother's name as primary holder and his name as secondary holder. Some deposits were also opened with his Mother's name as Primary holder and my name as secondary holder and some with my sister's name as secondary holder. All deposits have survivorship clause as (E or S) ans (A or S)Both my father and my Grandmother passed away recently, Grandmother died first followed by my father a week later. Following that we approached Tamilnadu Powerfinance, submitted all relevant documents, and all the fixed deposit proceedings were paid to me and my sister. Now, my question is, my grandmother has one other daughter (my Father's sister). Does she have a right to the fixed deposit proceedings, even if all the money was my father's to begin with ?