A Receiver, or more specifically, the amplifier component of a receiver … does not have an OHMS. Speakers have an ‘ohms’, which is actually a unit of measure for their impedance. Kinda like ‘pounds’ is a measure of ‘weight’, if you follow. But actually the impedance of a speaker varies with the frequency of the sound being output, which leads to speakers being rated based on their nominal impedance … which is more or less an average of its impedance.
Moving on … amplifier makers will often specify a ‘minimum recommended impedance’ for the speakers you run with them, but this only a recommendation. You can use any speakers with any amplifier. However, the lower the impedance (measured in Ohms) your speakers are, the hotter the amp will get, particularly as the volume increases. So if you use a low-impedance speaker (such as a 4 Ohm speaker), you either need an amp that’s rated to drive a low impedance speaker, or if not, you need to keep a lid on the volume you play it at, and/or provide a good deal of airflow around the amplifier, so as to keep it from getting hotter than it should.

Order now: Infinity Reference 263 Floorstanding Loudspeaker for $199.99 from harmanaudio.com