Content Organizer is used to route the documents based on the content type to a specified Document Library with in a site or another site . Drop off Library is a default library where all the documents will be routed when you don’t specify any target path. Drop off library is created when you activate the feature Content Organizer at Site Level.

Below are the steps to activate the Content Organizer feature

1. Navigate to Site Settings.
2. Go to Site features
3. Check for Content Organizer feature and activate it.

On activation of the feature, there are two new additional settings will be visible in Site Setting. They are

1. Content Organizer rules
2. Content organizer settings.

And drop off library is created automatically as well.

In order to set up the routing of documents to another site , you need to do the following

1. Enabled the Content Organizer in source site.
2. Created another sub site and activated Content Organizer in Target site.

3. Navigate to Site Settings and click on Content Organizer settings in Source site.
4. Go to Turn on the feature to “Allow Rules to Specify Another Site As A Target Location.

5.Create a Send to Connection in the destination site also

Hope it helps. Happy SharePoint Folks!!