Inheritance of a grandmother, 3 half-brothers and 4 half-sisters
15-9-2013 | IslamWeb
Question:
Assalaamu ‘Alaykum; Please calculate the inheritance according to the following information -Does the deceased have male relatives who are entitled to inherit: (A half brother (from his father)) Number 3 (A full paternal uncle) Number 1 (A cousin from a full paternal uncle) Number 7 -Does the deceased have female relatives who are entitled to inherit : (A grandmother from the mother) (A half sister (from the father)) Number 4
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
If the deceased did not leave any other heir than those mentioned in the question, then his grandmother gets one-sixth of the inheritance as her legal share. Buraydah 
said: "The Prophet assigned one-sixth of the inheritance for the grandmother if the deceased did not leave a mother.” [Abu Daawood and An-Nasaa’i - Both Ibn Khuzaymah and Ibn Al-Jaarood classified it as Saheeh (sound), and Ibn ‘Adiyy considered it as having a strong chain of narration]
Ibn Al-Munthir 
said: “The scholars agreed in a consensus that the grandmother gets one-sixth of the inheritance if the deceased did not leave a mother.”
The remainder will be divided amongst his half-brothers and half-sisters from the father’s side by Ta’seeb (by virtue of having a paternal relation with the deceased and not having an allotted share, so they get what is left after the allotted shares have been distributed); the male gets twice the share of the female as Allaah says (what means): {If there are both brothers and sisters, the male will have the share of two females.}[Quran 4:176]
The full paternal uncle and his sons will not get anything from the inheritance as they are prevented from getting inheritance because of the existence of the half-brother from the father’s side.
Therefore, the inheritance will be divided into 12 shares, the grandmother gets one-sixth, which is 2 shares as her legal share, each half-brother from the father’s side gets 2 shares by Ta’seeb, and each half-sister from the father’s side gets 1 share by Ta’seeb.
Allaah knows best.