Their name might deceive you but they actually do not share a part in the electromagnetic spectrum.
“The term ray is a historical accident, as cosmic rays were at first, and wrongly, thought to be mostly electromagnetic radiation. In common scientific usage, high-energy particles with intrinsic mass are known as “cosmic” rays, and photons, which are quanta of electromagnetic radiation (and so have no intrinsic mass) are known by their common names, such as “gamma rays” or “X-rays”, depending on their origin.”
They are high energy charged particles and travel at about the speed of light. They may contain particles with multiple energies and hence it is difficult to point out specific frequency for the cosmic rays. The frequency decreases with increasing energy of the particles.
“If you were to plot “cosmic rays” on an electromagnetic spectrum, it would basically encompass x-rays and everything higher in energy (higher in frequency or shorter in wavelength). I personally would leave it out, since I don’t think it’s a correct usage of “cosmic rays” (but I don’t make the rules).”
Dr. Eric Christian, NASA
So, the frequency at which cosmic rays must be operating would be anywhere more than 30EHz.