Fill the request to join crew form give real information if u want to be aproved 

• Fill the Form

A: you will be promoted if u are active many hours and active in gang attack with your team.

by missions increase your level rank in crew 

here is the list

• 1-10 (Thug)
• 11-20 (Hustler)
• 21-30 (Soldier)
• 31-40 (Trigger)
• 41-50 (Enforcer)
• 51-60 (Facilitator)
• 61-70 (Public Enemy)
• 71-80 (Shot Caller)
• 81-90 (Street Boss)
• 91-100 (Kingpin)

Special Ranks promoted only from leader of the crew some ranks have a special permission in the crew example invite other people to the crew 

here is the list

• The Starter rank is "MUSCLE"
• REPRESENTATIVES
• LIEUTENANTS
• COMMISSIONERS

and this is the hierarchy of crew