Seems like it's all down to next month's ECB ruling on ICL players, if he is only out of the Twenty20 he will be back.
http://www.thepress.co.uk/sport/4052159.Tykes_waiting_on_Rana_deal_and_ECB_ruling/
"Yorkshire chief executive Stewart Regan said: The latest news is that the ECB may only restrict Rana from playing in the Twenty20, in which case we could bring him over to play Championship, Friends Provident and Pro40.
If that is the case, we would bring him over so we, and him, could honour the final year of his contract.