Assalamualaikum . Please,Please answer this question. My grandfather has no own brother but 3 half brother . Now my question is that is wife of my grandfather's half brothers my mahram . Please answer this question

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Your uncle’s wife is not a Mahram to you; there is no difference in that between the father’s full-brother, or your father’s brother from the mother’s side only or from the father’s side only, as well as the brother’s wife.

Allah Says about the women who are permanently forbidden for marriage (what means): {Prohibited to you [for marriage] are your mothers, your daughters, your sisters, your father's sisters, your mother's sisters, your brother's daughters, your sister's daughters, your [milk] mothers who nursed you, your sisters through nursing, your wives' mothers, and your step-daughters under your guardianship [born] of your wives unto whom you have gone in. But if you have not gone in unto them, there is no sin upon you. And [also prohibited are] the wives of your sons who are from your [own] loins, and that you take [in marriage] two sisters simultaneously, except for what has already occurred. Indeed, Allah is ever Forgiving and Merciful.} [Quran 4:23]

Also, the Prophet said: “What is made forbidden (for marriage) by reason of breast-feeding is the same as what is forbidden by reason of blood ties.” [Al-Bukhari and Muslim]

For more benefit that what is prohibited by reason of lineage is prohibited by reason of suckling, please refer to Fatawa 85357, 140074 and 394765.

Allah Knows best.