Iām working on porting ROR for ES to 6.1.0 right now. Unfortunately, the plugin API has changed again, so now it requires a lot of massaging to get it to work again.
If anything, this is a good reminder of the added value ROR brings: now I get it why companies that choose to stick with ROR instead of creating their own plugin: porting an ES plugin code across versions takes a lot of time and requires quite some ES specific competences.