Being said that it is a shame for Evernote not to support RTL, I have found a workaround for that problem.
Create an RTL file in another application and put multiple line breaks (hit "Enter" key multiple times) to create a large space for you to write/edit.
Then copy that file's content to a new note in Evernote, and name it "RTL sample note" for example.
Every time you need to create a new RTL file, copy that note to the required notebook and start editing it in RTL format.
Have a good time.