The most common and most likely answer to this crossword clue is the 6 letter word REHEAR
I've seen this crossword clue in The Guardian
R
E
H
E
A
R
More clues leading to the result REHEAR
- Once again judge is stern about grunt of surprise
- Try again in seat occupied by male
- Try again to bring up having ambassador arrested
- The woman’s turned attention to judge again
- Listen to soldiers before getting to try again
- Ambassador stopping behind to try again
- Once more pick up what is found in train
- Back he goes inside to try again
- Try again?
- Try again to get her back and are foolish
Buddy explains!

The straight part
We know that "Try again" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case try again = rehear.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 REHEAR mean?
REHEAR verb- To hear again.
- To try (a lawsuit, etc.) again judicially.