Demanding equal share in the property

1) My father inherited a residential property. He expired in the year 2016. we 3 Brothers and 1 sister had given our rights on the property to our mother. And the property is transferred/Registered to our mothers name. 2) And now our mother sole owner of the property. 3) During 2021 our mother had been in agreement with a builder and given her consent to construct a apartment complex on 45:55 sharing ratio. 4) And our mother is entitled for 4 Apartment in the constructed apartment block. 5) We all siblings had given our NOC towards the deal. As such among our 3 Brothers – younger brother is in not good terms with our family and our mother is not interested to share the property equally to the 3rd Brother 6) On humanitarian grounds she will give some share to our 3rd brother. But the same will not be equal when compared to others ( Ie. 30% +30%+25%+15%) Distribution is 30% Each for 1st & 2nd Sons/, 25% For Daughter & 15% Share is for our 3rd Son. 7) For this arrangement Absolutely there is no objection from 1st & 2nd Son also from the Daughter. 8) As informed the apartment complex is completed. As per the agreement with the builder –Builder should transfer and register the property to our mother. Subsequently our mother will transfer the 4 Apartments to us through Gift deed. ( Building Share will be . 30% +30%+25%+15) 9) This property sharing details had been written by our mother and it is registered through a WILL in the sub register office during Oct 2022.Our mother is hale and healthy and she had Executed the Will on her own without any pressure or force from any one and she is fully aware of the inputs mentioned in the WILL. 10) Now our 3rd brother is demanding for equal share in the property. 11) Our question here is as such our mother is the sole owner of the property and we all children had given our rights on the property to her Can our brother claim/Demand equal Share in the property. As our 3rd brother is not in good terms with our Parents and family, our mother is not willing to Share the property Equally to him. Please reply