Your question is not clear, if the heir is committed to a mental institution, and no longer lives in the condominium, if the condominium is sold, he or she should still be a part of the distribution of the profits from the sale. If there is a trust set up for him or someone with a power of attorney to look over him and his matters, that person will be the one responsible for looking over these matters on his behalf. Without more information, it is hard to answer this question as it is very vague.