How is the inheritance of a deceased young man distributed among his mother, his father, his full brother, his seven full sisters, five paternal half-brothers, and one paternal half-sister?

If the deceased leaves behind only a mother, father, brothers, and sisters, then the mother receives one-sixth, and the remaining portion goes to the father by virtue of 'asabah (agnatic relationship). The brothers and sisters receive nothing, as they are blocked by the father. The inheritance is divided into six shares: one share for the mother, and five shares for the father.