Is it permissible to pay the rent for housing for siblings who are still studying and young, from zakat money?

It is permissible to give zakat to poor siblings, and this is better, for the Prophet, peace and blessings be upon him, said: "Charity given to a poor person is one charity, but charity given to a relative is two: charity and maintaining kinship ties."

However, if they have no money or earnings, and you are their heir and capable of providing for them, then it is not permissible to give them zakat; because their maintenance is obligatory upon you, according to the preponderant view, which is that of the Hanafis and Hanbalis. Whereas the Malikis and Shafi'is hold that their maintenance is not obligatory upon you, and thus it is permissible to give them zakat.