MINUTEMEN QUEST 06 - Form Ranks
Triggered by becoming an enemy of The Institute and talking to Preston Garvey
Note: You may skip this quest completely (it will not trigger, taking you straight to Minutemen Quest 07 - Defend The Castle) if you have already recruited 8 or more settlements to the Minutemen cause.
Objective: Talk to Preston Garvey about The Institute
After being kicked out of the Institute for declining to join them, attacking their personell or siding with another faction, talking to Preston will begin this quest. Preston will inform you (if you have less than 8 settlements) that the Minutemen need to become stronger before they can stand against The Institute.
Objective: Recruit more settlements for the Minutemen
So you'll be tasked with recruiting more settlements until you meet the required number. When you have enough, talking to Preston Garvey will trigger Minutemen Quest 07 - Defend The Castle and bring the current quest to an end.