Need Help finding who a cemetery plot belongs to in my family?

My Grandmother and Grandfather bought 8 plots in 1953 when my aunt was killed at 6 years old. My other aunt had a baby which passed at birth in 1961. Then in 1964 my Grandparents divorced. well my grandmother owned the plots and was buried in 1991. My grandfather then sold 3 plots after she died bc he had all rights well that left two plots he died in 1999 and was buried on his property not in the cemetery. He had two other children with his 2nd wife and had my dad with my grandmother his first wife the one who bough the plots. I know that it goes to all living heirs but im wondering if my dad has more right so him and my mom can be buried next to her