Hi Nayeli-
According to my 702T manual, 48.048kF will only work with 30ND. It’s used when film is being shot at 24fps and transferred to NTSC.
23.976 (or 23.98) is the real frame rate that an HD camera is recording when it says 24fps. As I understand it, if you are working with an HD camera shooting at 24fps, you want to be recording at 23.98…the REAL frame rate of the camera. 24fps is ONLY used when you are shooting film and finishing on film (for projection). In other words, not for HD transfer for television.
Of course, you should ALWAYS check with the post-house or at least the producer as to what you should set your frame rate and frequency to. NEVER second guess them after-the-fact, because you don’t really know how they plan on using your recordings. Plus, if they tell you wrong, it’s not your fault.
Hopefully some of this helps :o)
Dave J