There are plenty of Jewish genealogical societies around the world. Most of them are members of the International Association of Jewish Genealogical Societies (IAJGS) with following website https://www.iajgs.org
For searching members societies you have to specify as http://www.iajgs.org/blog/membership/member-societies/
The Netherlands are not member of the IAJGS, but can be reached through their website https://www.nljewgen.org
For Luxembourg you have to write to the Consistoire israélite du Luxembourg email@example.com or through their website https://www.synagogue.lu
But the most known Jewish institution for genealogical information with more than 26 million individual facts is jewishgen : https://www.jewishgen.org which is free for searching. With a yearly donation of 100 US $ you will be able to do more advanced search.
Any person noting an error or an omission is kindly requested to contact the editor responsible for it to make the change as soon as possible.