The official library does not claim to include every possible component.
For the symbol side you can use the generic connector symbol. I don't think we have a specialized symbol for RCA. So if you want a specialized symbol then you might need to create it your self.
I don't know if there is a footprint in the lib for such a connector. And even if there is one, you will need to check if you are able to buy a fitting component before using it.
RCA is standardized on the connector side but not on the pcb side. Every connector can have a different landing pattern.
So my suggestion would be that you first check what connectors are available to you. (What can you buy at a supplier of your choice)
And then make a specialized footprint for that component.
You might also want to check your manufacturing capabilities as i fear some of these connectors might require oval holes. This might not be supported by every PCB manufacturer. (Or it would result in a more expensive board.)