If you are interested to get into German PTs you should probably try to get into international trackers via interview or open registration and rank up to power user and build a track record. With that you could try getting into immortuos via their forum or get yourself recruited to RHD from an international tracker directly https://trackerpathways.org/?target=RocketHD&sort=days

Many German trackers don’t really do recruitment, only user invites which makes them hard to get into even if you are a desirable member.

Usenet works more similar to OCH. You need to pay for a Usenet provider (that actually has the data) and there are boards (forums) that host the metadata files that allows you to get the data you want from your provider.

If you can grab those via an API it’s called an indexer. The biggest German one Is called scenenzbs and always has open registration. So you could look around if you find the stuff you are looking for.

Btw are requests not a thing in the OCH community?

There is quite a bit of RTL+ content on German private torrent trackers and Usenet indexers