3 Answers, 1 is accepted
Putting checkbox on the right of the text is a tight to left option related to the UI requirements and guidelines. The only way to put the checkbox on the right is to use a CSS class that will make the Button to behave in tight to left mode:
Another option not to use right to left support is to use again CS class to override through it a few base CSS styles:
the Telerik team
I have just tried it myself with a later version (2019.2.514) of Telerik control and Bozhidar's suggestion works in all major browsers. Here is a short video demonstrating this: RadButton CheckBox On Right
If using Internet Explorer, I suggest double checking its configuration and ensure that it complies with the supported settings: Different appearance or behavior in Internet Explorer on local and production servers
If the issue still persist, I advise you submit a formal support ticket and attach an isolated version of this issue and my we'll investigate it locally. Later after we have the solution, we can share it in this forum post as well to make it available to everyone.