The most common and most likely answer to this crossword clue is the 6 letter word BYWAYS
B
Y
W
A
Y
S
Buddy explains!
The straight part
We know that "they’re off the beaten track" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they’re off the beaten track = byways.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 BYWAYS mean?
BYWAYS noun- A road that is not frequently travelled
- (by extension) an unpopular or arcane field of study