Gaurav From Kolkata want legal help in Property / Ancestral Property / Will

We belong to Hindu family. My mother had a second marriage after the death of my first father. My mother expired in 2018.My father(not my biological father,my mother’s second husband who also had his second marriage with my mother) expired in 2021.My step brother(his own biological mother was the first wife of my mother’s second husband) expired in 2022.My step brother had no other brother or sister except myself and was unmarried. My step brother’s grand mother who expired in 2012 gifted her property in 2011 to my step brother who had made a joint venture with a property builder with that gifted property and got 2 flats.There is no will made by my step brother.Only one aunt(sister of his biological mother) is still alive of my step brother.
Now as my mother,my father(2nd husband) & my unmarried step brother expired so can I claim those 2 flats which is in my step brother’s name or his aunt can claim the property?