Dear bhargavi,
In order to answer your questions, it would be good to know which degree program you have applied for.
Whether documents have to be submitted to the department next to the online application, or documents have to be uploaded as part of the online application, or whether no documents have to be submitted depends on the respective degree program. On the following website you will find this information in the PDF-document for each master’s degree program:
https://www.uni-hamburg.de/en/campuscen ... itere.html
Best regards,
BK