Is the brother the mother's brother? Or the mother's son? And are the siblings the mother's siblings? Or the mother's children?
IF this is parent to child/ren and IF there are no prior gifts/ inheritances, then the child in the house has no inheritance tax ( CAT). And as he is not selling the house, he has not made any gain and therefore has no Capital Gains tax.
IF this is sister to brother, there will be a CAT liability, unless they qualify for dwelling house exemption as per that Revenue link.
If the person in the house is going ahead with this, they will need a solicitor, who will be able to look at the specifics and advise.
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