The most common and most likely answer to this crossword clue is the 6 letter word INHUME
I've seen this crossword clue in The Times
I
N
H
U
M
E
More clues leading to the result INHUME
Buddy explains!

The straight part
We know that "put to rest" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case put to rest = inhume.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 INHUME mean?
INHUME verb- To bury in a grave.