The largest frequency range is gamma rays, but does the EM spectrum 'stop' somewhere? Like is there a limit to how large a frequency can get? Or how small frequency can get? Is it one of those things that theoretically nothing is stopping it, but nothing in the universe can produce ways of such a frequency or beyond a certain limit?

Does light from galaxies redshift to the point where the wavelength is just insanely long? Long enough that we can't see them?