Which of the following amounts to ‘dacoity’?

(1) Five or more persons attempting to commit dacoity (2) Five or more persons actually committing dacoity (3) One attempting robbery and four others are there to aid (4) One attempting robbery and four others aiding the commission of robbery

Option (3) is correct: All of the above statements amount to dacoity under Section 391 of the IPC as when five or more persons conjointly commit or attempt to commit a robbery, or where the whole number of persons conjointly committing or attempting to commit a robbery, and persons present and aiding such commission or attempt, amount to five or more, every person so committing, attempting or aiding, is said to commit 'dacoity'.