Is it possible to create a new message board using rest api?

You should be able to add a board to the community through rest.  The call is "/categories/id/[category id]/boards/add".  You should see this call documented in the Category section of the REST API doc.  

Query Arguments:

board.id (required) : string - Unique identifier of the board to be created.

board.title (required) : string - Title of the board to be created.