The criminal underworld on Pax Republica is comprised of a few key groups which operate both in concert and in competition with one another.
The first and largest group is the Hutt Clans. The Hutts have been involved in shady dealings since the moment they came into contact with the Republic, and are involved in the slave trade, illicit substances, and illegal weapons, among others. The Hutts control a large area of space bordering the Republic, within which the Republic has no jurisdiction; however, their business endeavours cross those boundaries frequently, and the Hutts are known criminals in many areas throughout the Republic. Because of their status as essentially an independent sovereign entity however, a large-scale crackdown on Hutt activity in Republic space would be diplomatically treacherous.
The Black Sun cartel is a criminal organization that took shape in the wake of the Sith occupation of Coruscant and the subsequent liberation. Black Sun is established on worlds throughout the Republic, but its largest and most profitable operations are among the Core Worlds, where they are involved in illicit substances, the slave trade, as well as weapons manufacturing and distribution. There have long been rumours that the cartel funds anti-Republic terrorists in an effort to sow chaos and imbalance, allowing them more freedom to operate under the watchful eyes of Republic Judicials without being the most important thing on the radar. The Republic has known about the Black Sun since their formation; however, they have been unable to extinguish the organization, or even make significant headway in infiltrating them, even after thousands of years.
The Exchange has been around almost as long as the Black Sun, but mostly sticks to the Outer Rim, where they are direct rivals of the Hutt Clans. The Exchange is known for ruthlessness, offering no quarter to those who have crossed them, or any who might get in their way. Even the Hutts and the Black Sun will make a deal when there’s opportunity for more profit, but the Exchange has always put vengeance over credits. Primarily engaged in acts of direct piracy and violence, the Exchange is more a loose association of independent criminals than a central organization, making it that much more difficult to track and eliminate.