Do brothers and sisters inherit from the estate of their deceased brother who is survived by a wife and living parents, and has no children?

Brothers and sisters do not inherit from their deceased brother if his father is alive, whether they are full siblings, or paternal or maternal half-siblings. Scholars unanimously agree that siblings, male or female, do not inherit in the presence of a son, a grandson (son's son), or a father. The father's share is not affected by his failure to provide financial support.

So, for someone who passes away leaving a wife, a mother, a father, and siblings: his wife gets one-fourth, his mother gets one-sixth, and the remainder goes to his father by way of ta'sib (residuary inheritance).