When trying out the LuSH-101 software synthesizer, the Renoise interface says “No presets available” even though the synth has presets.
The presets in LuSH-101 are file based and grouped by directories if that plays a role.
How can I make the presets show in Renoise?
As far as I know, you simply can’t make them show up in Renoise, as LuSH has its own preset format. 
Preset browsing in Renoise works only with plugins that use the VST standard preset format (.fxp, .fxb).
Are you using the demo version of that plugin?
It doesn’t seem to push its presets forward to Renoise.
The developer states that you cannot save presets in the Demo version. The demo might perhaps also not push its presets on purpose to prevent the host from saving the parameters but you should check that with the developers. There is also a push method that Renoise somehow does not support.
However when scanning for its presets, it has its files located in a temp/local settings folder.
For windows this is:
C:\Users[username]\AppData\Roaming\D16 Group\LuSH-101\Presets\
But these are not official fxp and bank files. However, you can alter these files using a text editor since the content is plain xml. This way you sort of can manipulate its default presets.
Thank you for the explanation. At least the presets are stored correctly on an instrument basis. I can browse and name them manually.
I do get the 64-bit demo plugin to crash Renoise 3 though… not sure why…