The most common and most likely answer to this crossword clue is the 6 letter word HARTAL
H
A
R
T
A
L
More clues leading to the result HARTAL
Buddy explains!

The straight part
We know that "industrial action" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case industrial action = hartal.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 HARTAL mean?
HARTAL noun- The closure of shops and offices, typically as a strike.