The most common and most likely answer to this crossword clue is the 9 letter word WELCOMING
I've seen this crossword clue in The Guardian
W
E
L
C
O
M
I
N
G
Buddy explains!
The straight part
We know that "putting out the red carpet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case putting out the red carpet = welcoming.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 WELCOMING mean?
WELCOMING adjective- Hospitable, accessible and cordial.
- To affirm or greet the arrival of someone, especially by saying "Welcome!".
- To accept something willingly or gladly.
- An act of giving welcome.