How to use the html tags in the diagrams

How to use the html tags in the gojs diagram

The general answer is that one cannot embed HTML inside nodes or links.

What is it that you want to accomplish? There might be a way that is more efficient than HTML.

I want to attach drop event to the diagram when the html component is drag and drop to the diagram.
And the Html object should have scope to the event so i can get the object from the event

Look at these samples:
http://gojs.net/latest/samples/htmlDragDrop.html
http://gojs.net/latest/samples/jQueryDragDrop.html

If you search all the samples you might find more examples of interest to you.