I'm not 100% sure of your situation.. but you can probably just add some CSS to your style.css document for titles. If you post your site's link I can give you the exact code but you can probably just add:
to your CSS file.
Look at 3 Different Ways to RTL your CSS for more help.
EDIT: I did just realise that you have both English and Arabic on your site... and adding that code will align ALL titles to the right. In this case... the simplest solution I can think of (but very messy), is to add the following code in your titles for Arabic posts (this is also without messing with style.css but if you'd rather do that then you can do it that way too):
<div style="text-align:right;">YOUR TITLE HERE</div>
That should work.