Titles cannot be copyrighted or even registered.
The word “avatar” cannot be copyrighted and as use in a title it
cannot be restricted by anyone. The MPAA title registration is so
producers can find out if another producer (or studio) is planning
on using that name. As Adeimantus already suggested, two movies
with the same title at roughly the same time can create confusion
and thus marketing troubles. But there can be multiple movies with
the same title. The more “famous” and popular a movie was the more
likely the producer (or studio) will go to the law to protect it.
But they don’t sue or give a cease and desist order for common
word titles. They can only pull rank if they can prove there will
be a reasonable confusion in the marketplace.
Owen, one way to check if your title has been used is to check
IMdB. Not the end all of research but that data base does have a
lot of movies listed. You can also use Google - use quotation
marks around your title.
Here in the States a business name is registered in several
different ways. In Australia you should look at
Australian Business Register
