I want to add the attribute dir="rtl" in <html> tag of the pages, but I don't see any html code in my project structure or root page html where this html tag is present. Is there any way to do it without using JS in AEM 6.5?
In your overriden core page component, in page.html file add the dir attribute. If you want, you can also make the dir attribute as configurable in page properties.