Do you possibly have only LabVIEW base version? You probably need at least the full version for these VIs.
Also make sure that the "Palette View" is not set to basic. It should be at the default setting.
I just fired up my old 6i and the real
sine wave.vi is in:
Functions..Analyze..Signal Processing..Signal Generation..Sine Wave.vi. (See image 1).
However, for the activity you actually need the
Sine Waveform.viFunctions..Waveform..Waveform Generation..Sine Waveform.vi. (See image 2)
What LabVIEW version (Base, Full, Professional, etc.) do you have?