Partitioned Joint Property of parents rights to married daughters

20 Years ago My father & his four brothers partitioned ancestral property and constructed commercial complex(Jointly) I am the single son and two daughters to my father. I expended Rs.15 Lakhs for construction, as My father unable to construct on par to his brothers. Due to my commitment & responsibilities to my family, my father Registered a will in favour of me, that i should get all rights after his death. Recently my father dead & I executed will and mutated in Muncipality with all Legal formalities (like Affidavits) But, My sisters(married)demanding rights on property, how it possible..?