Property dispute with step brother

I am living in an apartment since 40 years. It was bought by my father when he was alive on the name of my step brother, because I wasn't born then. Later, my father made a will in which he mentioned that the same step brother had forged his signature to dupe him off of his other properties and sold it off. In my father's will, there is no mention of this apartment I am living in ever since 40 years. In fact, ever since the day this apartment was bought, not even for a single day anybody else, including my stepbrother, has lived in. Only my father, my mother and I have lived in here. 10 years back, my father passed away due to long illness. My stepbrother never questioned our custody or possession of the house in these 40 years, not even after my father passed away. And now the building is going under redevelopment, and he is not ready to transfer the apartment on my name. We have paid all the bills and the maintenance of the apartment all these 40 years. Please guide. I am the only daughter to my father and we are a Muslim family