samymassoud Given how extensions and language packs work in Flarum, it would probably be best if you released them as two separate packages rather than as a combined package. Among other things, that would allow you to maintain and update them separately.
I think it should even be possible to specify your RTL extension as a prerequisite for your Arabic language pack, so that whenever someone tries to install the language pack, Composer will make sure the RTL extension is there too. @Toby or @luceos would know better than me whether that's possible, and how to go about setting it up.