...
In RealFlow's “Statistics” panel which is available for → Hybrido domains and → SPH emitters. Under “V min/max” you can see the values.
In the “RealFlow RenderKit Particler” node's → “Preview Object (3DS)", → “Display “Display (C4D, HOU, MYA, LWV)", or “RkViewer “RkViewer (XSI)" panel. The values are displayed under “(Current) Min/Max”.
...