Telerik does not provide any control to deal with your requirement. The align attribute of <legend> is deprecated
in HTML 4.01 and it is no longer supported in HTML5.
Still this works in most browsers but "you should use CSS to pass the
validation". You can set "margin: auto" to the <legend> which
works fine in IE and Chrome. In Firefox you need to give custom styling
to center the legend such as margin-left:45%.