Division of inheritance among a mother, father and four brothers
Question

                A person died, leaving behind a mother, father and four brothers. How should the inheritance be divided?
Praise be to Allah.There are two views concerning this matter 
          among the scholars.  
The first view:  
This is the view of the majority, and is the 
          correct view among the Hanbali madhhab. This view states that if there 
          are two parents and a number of siblings, the mother gets one-sixth 
          and the rest goes to the father, because of the words of Allaah (interpretation 
          of the meaning):  
“… if the deceased left brothers 
          or (sisters), the mother has a sixth…” [al-Nisaa’ 
          4:11]  
The general meaning 
          of the aayah indicates that the presence of siblings reduces the mother’s 
          share from one-third to one-sixth, whether they inherit or not.  
          
Al-Ramli, who was a Shaafa’i, said: “Know 
          that for a person to be able to prevent another person from inheriting 
          or reduce his share, he should himself be allowed to inherit. Whoever 
          does not inherit for a reason that may be mentioned later cannot prevent 
          anyone from inheriting altogether or decrease the amount he inherits, 
          except in a case such as when brothers are prevented from inheriting 
          by the presence of the father, but the mother’s share is reduced from 
          one-third to one-sixth because of their presence; and when her two children 
          are prevented from inheriting by the presence of their grandfather but 
          their presence reduces the mother’s share to one-sixth; and when there 
          are a husband, a full sister, a mother and a brother from the father’s 
          side, the brother has no share even though when combined with a full 
          sister this reduces the mother’s share to one-sixth.” 
Nihaayat al-Muhtaaj Sharh al-Minhaaj, part 6, 
          p. 16  
The view 
          of the Maalikis is: “Everyone who cannot inherit anyway cannot prevent 
          an heir from inheriting or reduce his share” – except in five cases… 
          the second of which is: parents and siblings, where the mother’s share 
          is reduced to one-sixth and they (siblings) cannot inherit because they 
          are prevented from doing so by the father.
See Haashiyat al-‘Adawi, part 2, p. 388  
          
The second view: 
That she gets one-third 
          along with the brothers whose share is reduced because of the presence 
          of the father. This is the view of some later scholars and it was the 
          view selected by Shaykh al-Islam Taqiy al-Deen Ibn Taymiyyah, but the 
          rest of the scholars differ from him.  
Their point is that the siblings do not reduce 
          the mother’s share to one-sixth unless they have the right to inherit 
          – so that they would benefit from reducing the mother’s share. The evidence 
          for this is the aayah (interpretation of the meaning):  
“… if the deceased left brothers or (sisters), the 
          mother has a sixth…” [al-Nisaa’ 4:11]  
where the father is not mentioned. The ruling 
          here refers to when the mother is on her own with siblings; after the 
          mother is given one-sixth, the rest is to be given to them. Among the 
          contemporary Hanbalis, this view was favoured by Shaykh ‘Abd al-Rahmaan 
          ibn Naasir al-Sa’di, when he said: “The correct view is that the brothers 
          who are prevented from inheriting or whose share is reduced do not prevent 
          the mother from inheriting one-third, because Allaah says (interpretation 
          of the meaning): ‘…if the deceased left brothers or (sisters)…’, 
          meaning heirs. As these brothers who are inheriting are not described 
          as being prevented from inheriting, so none of them can be prevented, 
          because the ruling on the division of inheritance is that the one who 
          does not inherit cannot prevent another from inheriting whether in whole 
          or in part. The reason for reducing the share of the mother is so that 
          they can have a share, but if they are not heirs they cannot prevent 
          anyone else from inheriting.  And Allaah knows best.  
See al-Tahqeeqaat al-Maradiyyah by 
          al-Fawzaan, p. 87-88  
Shaykh al-Islam Ibn Taymiyah (may Allaah have 
          mercy on him) said:  
Siblings cannot reduce the mother’s share 
          from one-third to one-sixth except if they are heirs, whose share is 
          not prevented by the presence of the father. In the case where there 
          are two parents or two brothers, the mother’s share is one third. The 
          presence of the grandfather prevents the brothers from inheriting, thus 
          the brothers could not reduce the share of the mother because they themselves 
          are prevented from inheriting, according to scholarly consensus. The 
          same applies with regard to parents or the father. This was narrated 
          from Imaam Ahmad and was the view selected by some of his companions, 
          and this was the view of Abu Bakr and others among the Sahaabah (may 
          Allaah be pleased with them). 
See al-Fataawa al-Kubra, part 5, p. 446 
Since there 
          is scholarly dispute on this matter, you should refer to the qaadi (Muslim 
          judge) in your country, because the ruling of the judge will dispel 
          the differences.
And Allaah knows best.