The most common and most likely answer to this crossword clue is the 2 plus 4 letter word AT HOME
I've seen this crossword clue in The Times
A
T
H
O
M
E
More clues leading to the result AT HOME
- In moat he swims
- In a mo, the dancing
- In order, two articles written about that
- In two articles, order maintained
- In the moat, not all swimming
- In a book, hotel besieged
- In articles about poems, odd bits missed
- In a book about the beginning of history
- In a book, heroic opening captured
- In hotel, gripped by a book
Buddy explains!

The straight part
We know that "In" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in = at home.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.