Sorry about English. :/
Just a short theory. :)
I think RJ is Ron.If not,he has some connection with him.
I mean look at this guy,Bruno Heller told that RJ is someone who is barely seen in the series.
Ron is that guy.
Important Clue:
RJ is holding a cup of tea with his left hand in Red Is The New Black.
Look at the sceen in 6x03 when Jane told Lisbon:"I could marry you off in a minute.",then he says:"Hi Ron".
In that sceen Ron is holding a file with his left hand just like RJ hold the cup of tea.I FORGOT TO MENTION(Sorry about that :/ ) :He has got a same ring as RJ on scene with a cup of tea and he is seen in almost every episode but only on a second.
I think that extra informations will help you guys. :)