Renier, I am copying a message from a good friend of mine whose family is from Oradea originally, then moving to France.  She has some good hints for finding the information that you need.  She says that you can write the Jewish community (link below) in English.  They are very helpful:

There is – or was a Jakab family from Nagyvarad – today Oradea, ten persons of that name were deported on May 3, 1944. I could let you have their names if it helps. I believe your best bet is contacting the Jewish community in Oradea such as it is. Let me find the link for you and think of other ways to help.

Doesn't the relative have a copy of his identity card? Hope all this is helpful.

https://www.facebook.com/ComunitateaEvreilorOradea/



Shimona Kushner