That's a wise question IMO, since you asked it instead of guessing. To connect a pair of KM 184s to the balanced inputs of your recorder, any good-quality XLR-3 cables can be used. The mikes require 48-Volt phantom powering, which the Zoom H6 offers.
Active cables aren't a consideration for the type of microphone that you have, but here's the explanation: They allow a person to run just the capsule of a condenser microphone at some distance from its amplifier/body without loss of signal quality, since the crucial first stage of the amplifier circuitry--the impedance converter--is built into the cable socket that the capsule screws onto. You then connect the other end of the cable to the microphone's amplifier/body, which can be a few feet away.
A capsule on one of those cables is smaller, lighter, and easier to suspend and/or conceal than the complete microphone would be. However, the amplifier has to provide the operating current for the cable's circuitry, plus the capsule has to work acoustically on the neutral physical fitting of the cable socket. Neumann created the KM 180 series in 1993 to be a simplified, lower-priced counterpart to their modular KM 100 series (1988), and its design omitted both of those characteristics. (There was also a patent issue which I won't go into here.)
--best regards