The most common and most likely answer to this crossword clue is the 12 letter word ACADEMICIANS
I've seen this crossword clue in The Times
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More clues leading to the result ACADEMICIANS
Buddy explains!
The straight part
We know that "Institute members" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case institute members = academicians.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 ACADEMICIANS mean?
ACADEMICIANS noun- A member (especially a senior one) of the faculty at a college or university; an academic.
- A member or follower of an academy, or society for promoting science, art, or literature, such as the French Academy, or the Royal Academy of Arts.