Kolibri on RACHEL performs with the same functionalities and has the same available content channels for import as it does if used standalone. However, there’s some overlap between the content sources that are available in OER2Go and those that have been made available for use in Kolibri (such as CK-12, PhET, and Khan Academy, among others).
You can access a full list of the existing public channels that can be imported into Kolibri by selecting Kolibri Studio as your import option. There may be other overlap in content libraries that isn’t reflected on OER2Go, but the updated Kolibri Library list is available when connecting via Studio. If there are particular modules on OER2Go that aren’t listed as channel options in Kolibri but that you are wanting to use inside Kolibri via RACHEL, then there would need to be a conversation with the LE team to determine if the content source could be brought in as a Kolibri channel. But it’s not quite as straightforward as accessing any of the existing RACHEL modules in Kolibri.
I hope this helps and we understand where there may be confusion, as both Kolibri and RACHEL play a content repository role, with each having a largely different set of available content.