Meanings:
\textit{Cacophonic} — harsh-sounding; related to unpleasant noise.
\textit{Cacographic} — badly written/poor handwriting or spelling.
\textit{Calamitous} — disastrous, involving great misfortune.
\textit{Catastrophic} — disastrous, involving catastrophe.
\textit{Contraindicative} — serving as a reason against a course of action (esp. in medicine).
\textit{Cataclysmic} — violently destructive; disastrous.
Grouping:
“Calamitous”, “Catastrophic”, and “Cataclysmic” are near-synonyms meaning {disastrous}.
The others denote unrelated ideas (noise, handwriting, medical caution).
\[
\boxed{\text{Hence, III, IV & VI only.}}
\]