Hi Kushagra,
Thank you for contacting us!
If you are going to identify the elements in the user's selection, I would suggest you to create a new document from the selection. Then you should enumerate its table/image elements and determine whether they exist.
The following code-snippet demonstrates how this could be accomplished:
I hope this helps!
Let me know if you have other comments or questions.
Regards,
Yancho
Telerik