If you come across a issue where you can't see SSRS Content types in your site, then first thing to try would be to deactivate and active the site collection feature "Report Server Integration Feature".
If you still have issues and can't see them and reckon there's some issues with configuration, then try re-installing the content types by following the instructions provided in link below:
Below is the excerpt from the article.
To install the files but skip the custom action phase of installation, run the rssharepoint.msi from the command line with the SKIPCA option:
- Open a command prompt with administrator permissions.
- Run the following command:
Msiexec.exe /i rsSharePoint.msi SKIPCA=1
The installation user interface will open and run as normal and the rsCustomAction.exe file is installed. However, the .exe will not run at the end of the installation and rsCustomAction.exe will remain on the computer when the installation is completed.