Yes—an IR-converted camera still records three channels, and in the near-infrared range they are not identical. After removing the camera’s IR-cut filter, the sensor’s red, green, and blue pixels retain somewhat different sensitivity from roughly 700–900 nm, so you can treat them as three different near-IR bands. Beyond about 900 nm, their responses become much more similar. In practice, the channel separation is limited, but it can be emphasized in post-processing, for example by increasing saturation or remapping channels.

If you want stronger spectral separation, a common low-cost approach is to shoot multiple exposures with different infrared bandpass filters mounted on the lens, one at a time. That gives you several narrower IR bands, though not in a single shot.

For more advanced multispectral or hyperspectral imaging, people use dispersive optics such as prisms or diffraction gratings to spread light into a spectrum, but that is a different setup from a standard converted camera.