Snubber design for switching an inductive mains load with a relay
The RC network's purpose is to provide a dampened path for the charge stored in the inductor. The MOV and TVS diode purposes' is to limit the high voltage that may appear. So they're complementary. Use both a RC network plus either the MOV or TVS.

I used 100 nF + 100 ohm for my loads for years and never had any problems so that's a couple of starting values.