In order for Wordpress to properly find your localization files, they have to be in the directory specified in either the second argument of load_theme_textdomain
or the third of load_plugin_textdomain
.
Be careful that your .mo files must be named exactly like the locale. In your case it has to be fa_IR.mo
. In the case of a plugin, the name of the plugin must be prefixed to the locale with a dash, such as: my-plugin-fa_IR.mo
.