Rank explanations

Pakhan

The Father, or Pakhan, is the Don. His word is law, and he controls the whole organization.
Though his Pravaya Ruka and Brigadiers, he passes his messages and orders to the lower ranked members.

Pravaya Ruka

The Pravaya Ruka is literally the Righ Hand of the Pakhan. The Pravaya Ruka has just as much to say as the Pakhan, and is usually family or a very close friend.

Sovetnik

The Counsellor, or Sovetnik, advises the Pakhan and Right Hand, and passes along messages to the Brigadiers while the top leaders are out of town.
The Counsellor also takes care of most of the rankings, and suggests members to be either promoted, demoted, or killed. He has a very important role for the organization, and may also be sent to negotiate with hostile organizations, representing the Pakhan or Pravaya Ruka.

Brigadier

The Brigadier is controlling the members of the organization, the whole foundation is laying on his shoulders.
The Brigadier must keep his men entertained, and also recruit new men for his crew. He needs to gather money for the organization, and take over new turfs, as well as represent the organization on the street.
If anything goes wrong during a robbery, break in or any other of the organizations operations the Brigadier who was in charge will be the first to blame - which usually ends in the death of the Brigadier. The Brigadier must also have atleast one Avtorityet to help him, being like the Pravaya Ruka is for the Pakhan. There's almost only up to 4 Brigadiers, to make sure that the crews are full, and not a ton of small crews working almost independently.

Avtorityet

The Avtorityet is like the Soldiers are for the Cosa Nostra. They're pure muscle, and their purpose is to fight, and spread the word about the organization.
They have little or none administrative power, yet they're an active part of the recruitment, as they're walking the streets for potential buyers of drugs, weapons or whores.
There can be an infinite amount of Avtorityets, but it's rarely seen that there's a lot of them as they do need to train new Vors and associates.

Vor & Shestyorka

Vor is an honorary title of the organization. It means thief, and it means you're officially in the organization. This also means that you're allowed to boss around associates, as there's a big leap between the associates and thieves. Associates, or Shestyorkas, are new to the organization, and they have no influence at all. There's no limit on how long a person can remain an associate, and it's hard to get promoted, you'll need to show the Pakhan and Pravaya Ruka skills, and a strong concience as well as be able to take orders.
There's stories about fresh associates who impressed the administration enough to go from associate to Avtorityet.