The most common and most likely answer to this crossword clue is the 6 letter word DURIAN
I've seen this crossword clue in Financial Times
D
U
R
I
A
N
More clues leading to the result DURIAN
Buddy explains!

The straight part
We know that "tropical fruit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tropical fruit = durian.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 DURIAN mean?
DURIAN noun- Any of several trees, genus Durio, of Southeast Asia.
- The spiky edible fruit of this tree, known for its strong taste and very strong, unpleasant odor.
- A yellow colour, like that of durian flesh (also called durian yellow).