Hi, i tried to create with the rest attribute a custom aov with rendervar lop node, inside houdini all work as expected but when i import in nuke i lost the beauty and i see instead the rest attribute and other aovs like direct diffuse for instance.

Could it be Nuke having trouble reading multi-part EXR format? Can you try adding "--exrmode 0" to husk command line to write in legacy EXR format and see if it helps?

i found a way, if i create that aovs inside the karma node adding new rendervars from that instead using the rendervar node work fine in nuke, i could try with that, but if multiexr don't work shouldn't be find also the other aovs inside the multiexr instead the other aovs created like direct-diffuse inside karma rendersetting node work as expected

It sounds like your render product had the rendervars replaced and not appended to--so it didn't even save the beauty. Can you post a hip file?