That would be open (infinite resistance = no connection).
They should measure approximately zero-Ohms (a "direct connection" or a "short") end-to-end where there should be a connection and open where there shouldn't be a short.
Low resistance measurements are difficult to do accurately. No meter is "perfect" and there is resistance in the leads and the connections at both ends of the probes. As long as you read
near zero where there should be a connection and infinity where there shouldn't be a connection, everything is fine.
Good! Most audio cables don't affect the sound (as long as it's the appropriate type of cable). And headphone cables are generally the least critical.
If they are working there's no need to measure them.