There's tons of organized crime in Germany. As far as "domestic" organized crime in Germany goes, it's mostly connected to bikers. Mostly German guys and Turkish guys born in Germany are members of outlaw motorcycle gangs. They're very heavily into operating brothels, security, drugs, etc...

Aside from that Germany is a playground for international organized crime, even though not every organized crime group present in Germany is doing heavy lifting.

Ndrangheta, Camorra, Sicilian mafia, SCU...are all present in Germany, but they mostly use Germany as a money laundering spot. A ton of gelaterias, pizzerias, etc...are Italian OC connected.

In Berlin, Bremen and the Ruhr there's infamous activity by Lebanese clans. There's the well known Mhallami/Mardelli clans in Berlin, Bremen and Essen and you also have Hezbollah-connected Shi'ite clans in Duisburg, Dortmund and Berlin. Always large extended families of which not every family member is a criminal and the heavy criminals are a minority in these families, but the number is disproportionate. They're mostly involved in large-scale theft and drugs and are designated as Germany's number one "foreign" crime problem.

Turkish and Kurdish organized crime continues to operate in Germany due to a huge community from Turkey in the country. A lot of infamous Turkish criminal organizations from the Black Sea region and Kurdish clans from East and Southeast Anatolia have operated and still operate in Hamburg and the Ruhr especially. Of course you also have criminal organizations consisting of German-born Turks that operate in conjunction with organizations based in Turkey.

OC from the Balkans is over there as well. Albanian organized crime is a very heavy all over Germany and you also have Serb/Montenegrin and Bosniak organized crime over there. Serb/Montenegrin OC used to be heavy in Frankfurt and East Germany, but nowadays they just use Germany as a money laundering spot.
In Freiburg there's also a big community of Bosniaks from the Sandžak and organized crime from that community at one time made some noise as well.
Bulgarian OC and Romanian OC have stakes in brothels as well, but those groups just focus solely on prostitution.

OC from Russia and other former Soviet states are all there as well, mostly in East Germany. Russian, Georgian, Armenian, Chechen, Azerbaijani, Ingush, Dagestani and Yezidi groups are all active in Germany. There's quite a bit of Armenian and Georgian OC in Erfurt especially and activity by groups from Moscow, Saint Petersburg and the North Caucasus in Berlin has been noticed as well. Just like the Italian groups, these groups mostly use Germany as a money laundering spot.

Polish and Lithuanian OC is largely involved in car theft rings and contraband cigarettes.

On the border with the Czech Republic there's also quite some Vietnamese OC; they mostly concentrate on counterfeit goods, marihuana and meth production.

Afghan gangs are also involved in heroin in Hamburg, the Ruhr and Stuttgart. They're not as big as the Turkish and Kurdish groups, but they've become noticeable as well. The Afghan community in Germany seems to be different from the Afghan community in for instance Belgium. In Belgium a lot of Afghans are Tajik refugees, but in Germany a large amount of them are Pashtun with family connections in the opium-growing regions of Afghanistan. So there was at one time talk that they were about to become serious competition for the Turkish and Kurdish groups, but that has cooled down a bit.

Another noticeable thing in the Ruhr is that Romani gypsy clans with origins in the former Yugoslavia (especially Bosnia) set up shop there as well. Noteworthy about this is that these clans originally migrated from Bosnia to Rome and seem to have a lot of Italian OC connections. A few years ago a member of a famous Belgium-based crime family was hit by members of one of these gypsy clans, who were supposedly hired by a Camorristi who was entangled in a conflict with said Belgian crime family.