Hi Malalai,
I had never done this before so I gave it a try.
There is already a class defined is-rtl which once applied in the layout will apply the "right-to-left direction" to everything. There is an ExtendedClass attribute in the Layout blocks, which is great to apply the changes at a root level to affect everything:

I am not knowledgeful of RTL languages to be able to say 100% confident that it covers all our scenarios but it should definitely be a good start.
In attachment you can find a simple OML with a toggle RTL / LTR that applies the aforementioned change.
Regards,
João