Hello @kartik,
To copy HTML , you can do the following in IE ONLY. This is is fundamentally different from the other methods, as the browser actually visibly selects the content.
// create an editable DIV and append the HTML content you want copied
var editableDiv = document.createElement("div");
with (editableDiv) {
    contentEditable = true;
}     
editableDiv.appendChild(someContentElement);          
// select the editable content and copy it to the clipboard
var r = document.body.createTextRange();
r.moveToElementText(editableDiv);
r.select();  
r.execCommand("Copy");
// deselect, so the browser doesn't leave the element visibly selected
r.moveToElementText(someHiddenDiv);
r.select();   
Hope it helps!!
Thank you!!