DU allows edits in your application only until you make the payment towards the application. But once you make the payment towards the application, you cannot make any changes to it. Question 5 of FAQs available at https://ug.du.ac.in/index.php/site/faq says " you can rectify error by logging again into your account through the “Edit” button at the end of each session/page till the online registration portal is open & the fee is not paid." So if you have paid the application fees, it is highly unlikely that you can make any changes to the application. Having said that, we would request you to reach out to the helpdesk at undergraduate2020@admissions.du.ac.in  or pg2020@admission.du.ac.in (mailto:pg2020@admission.du.ac.in) based on the course you have applied for. Because DU is allowing second registrations for justified cases. Please mail them form your registered email id and they will respond within 24-48 hours. And you can take a call based on their reply to your issue. Make sure you mention the reason as to what you mean by right attachment,