The Megazyme K-FRUC kit can be employed to detect inulin, fructan and fructooligosaccharides. If your sample contains all of these they will be detected as a whole and not individually.
Free fructose would not be measured here as it would be converted to a sugar alcohol after borohydride reduction.
Please see the following FAQ which details how you can measure free sugars if required:
Can I use the F-FRUC assay kit to determine inulin plus sugars in my sample separately?