looks like no entries in the registry.
Is NX feature installed in RAC?
Open cmd in portal dir and execute runner -mime=application/ugmportal. Another shell should pop-up. If nothing happens you have to add the installation or manually some entries to registry.
Best practice is to install NX first then TC. There should be a PORTAL_ROOT\start_nxmanager.bat script if the NX integration is installed. If you had a previous version of NX installed then the registry setting could still be pointing to the old location. Search for start_nxmanager.bat in the registry and validate the location is correct.
NX 11.0.1.mp01 | SW 2016 | TcUA 11.2.3
you must have 2 bat files "nxmanager_portal" & "start_nxmanager" under "C:\Program Files\Siemens\Teamcenter11\portal" if you have installed "Teamcenter Integration for NX". If not then please install the same using TEM. You can find TEM at "C:\Program Files\Siemens\Teamcenter11\install". Double click the TEM and you can find "Teamcenter Integration for NX" in under "Extensions". I have attached a screen shot.
you really have to make sure that the registry entries are there.
Do you see start_nxmanager.bat here [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ugmportalfile\Shell\Open\Command] in the registry?