Dear Mritunjay,
The CRED edit link just render the form in the single page of the post, adding a paramenter to call the form like: ?p=23&cred-edit-form=45
So, if you want to change its template, you should change the content template of the custom post. But you can not have a different template for CRED edit page and for the single post page.
Please let me know if you are satisfied with my answer and if I can help you with any other questions you might have.