In drupal 7, Is there other ways to assign blocks to regions without doing it in admin/structure/block or in panels? I have this client and i can't seem to find where they are actually assigning the blocks to region. They are not using panels, and the there are no assigned blocks in admin/structure/block
Thanks.
One easy way is to use Context module : https://www.drupal.org/project/context
Your description seems to be a use case of this module ;)
With it, you will see nothing assigned in admin/structure/block. just a new menu "context" in which you will find some context, wich conditions and reaction. the logic could be something like
"I am on the /toto/tutu page, so block 1 is in region R1 and block 2 is in region R2".