Who would be the legal heir of a spinster?

An unmarried lady dies at 60 years. She has not adopted any one. Her parents died 10 years ago.She has two brothers who are alive. One of them is elder and the other younger. She has among other things a flat. This is put on sale.Who would sign as the legal heir: Elder brother or both the brothers? In case both of them sign, will there be any problem to the elder brother who does have not issue and wants to donate almost all of his self earned ets to a charity?