The most common and most likely answer to this crossword clue is the 4 plus 2 letter word TOSS UP
I've seen this crossword clue in The Daily Telegraph
T
O
S
S
U
P
More clues leading to the result TOSS UP
Buddy explains!

The straight part
We know that "Take a chance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case take a chance = toss up.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.
Crossword Answer definitions
TOSS UP noun- A decision in which neither choice is clearly favorable or unfavorable, or for which the outcome does not matter.
- Either of two outcomes that are equally likely.
- The toss of a coin used to decide some issue.