I can't find a Renderman node in the TOP nodes list:
https://www.sidefx.com/docs/houdini/nodes/top/index.html [www.sidefx.com]

Exists any official way to use renderman inside TOP networks ?

Thanks.

It's not wrapped nicely like the ROP Mantra node, but there exists renderman ROPs and you can use a Rop Fetch to point to that.
Actually if you dive into the ROP Mantra TOP node, you'll see it's actually an HDA that is doing exactly that.