The most common and most likely answer to this crossword clue is the 6 letter word ALLOWS
I've seen this crossword clue in The Guardian
A
L
L
O
W
S
Buddy explains!

The straight part
We know that "Permits" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case permits = allows.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 ALLOWS mean?
ALLOWS verb- To grant, give, admit, accord, afford, or yield; to let one have.
- To acknowledge; to accept as true; to concede; to accede to an opinion.
- To grant (something) as a deduction or an addition; especially to abate or deduct.
- To grant license to; to permit; to consent to.
- To not bar or obstruct.
- To acknowledge or concede.
- To take into account by making an allowance.
- To render physically possible.
- To praise; to approve of; hence, to sanction.
- To sanction; to invest; to entrust.
- To like; to be suited or pleased with.