The Detroit Resistance (Also known as either the Militia, DR, or just the Resistance) is a heavily armed criminal

gang in Detroit formed by former members of the Agni Kai Triad, Terra Triad, and Templar Order, and is backed by Kuvira and the Earth Empire, as well as Charon Industries, in which the gang runs guns made by the umbrella company.
Although stationed in Detroit, they won't appear in Part 6. They'll still be in Book One.