I have a Philips sound bar and I'm trying to hook it to my ruko tv using RCA jacks is it possible
No, if your roku tv had rca jacks, or phonoplug to accept a breakout cable with rca jacks on it, in both cases the rca is an input, you need an output to send the sound to your soundbar. The only audio outputs on a roku tv are hdmi-arc or optical output. Sorry.