The most common and most likely answer to this crossword clue is the 6 letter word ANTI-G
I've seen this crossword clue in The Guardian
A
N
T
I
-
G
More clues leading to the result ANTI-G
Buddy explains!

The straight part
We know that "kind of suit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case kind of suit = anti-g.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ANTI-G mean?
ANTI-G adjective- Counteracting the g-force of acceleration.