Who has the right to bear coat of arms?
Everybody does, with all the usual exceptions. In just about every country, the right to “wear” arms is not controlled. One notable exception is England, which has very restrictive legislation on the subject. A fair summary of the overall situation is that anyone who wants to display his, or her, or their, or its, arms, can do so. The main thing is to meticulously respect the age-old rules of heraldry, and never, never, never call your own the coat of arms that belong to someone else.