Additional info:
Solaris City Police Dept. (International area): Limited influence but highly skilled and professional. Officially Lyran employees, reputation from the Chief on down for being incorruptible and dedicated.
Federated Commonwealth Police Dept. (Black Hills, Silesia): Nearly a thousand well equipped officers with support vehicles and a lance of recon mechs modified for crowd control, housed in a facility in the heights above the slums of the Black Hills.
Cathay Security Station (Cathay): A heavily fortified garrison housing a strong, well-armed, and professional force loyal to House Liao. Light mechs are available to accompany major security sweeps or put down disturbances. Despite this show of force, the Maze (Cathay's worst slum) remains off-limits to the security forces.
Kobe Security (Kobe): 500 notoriously hard-nosed troops loyal to House Kurita maintain the peace in Kobe. Their harsh but effective techniques may be supplemented by APCs and mechs if need be.
Montenegro Civic Authorities (Montenegro): the Solaris players' guide contains little info about House Marik's police force in the city. The most detailed bit of info is that their offices are located in the gleaming Marik Tower. The most telling is this sentence: "Possibly the ugliest of the Solaris sectors, Montenegro has deep troubles with crime and gang violence."
In the sprawling slums beyond the city proper many of the smaller realms (even some Bandit Kingdoms) maintain their own districts in imitation of the Big 5, but they are neither officially recognized nor detailed in the book
I hope that info helps, and if you need more let me know. I can scavenge up more tidbits from the Players' and GM's books.