1. Use the analog audio or headphone out of the RCA if it has them.
2. Use the optical audio output with a DAC to convert it to analog for the Sony.
3. If the TV doesn't have any audio outputs you can't connect it to the Sony without modifying the set.
There are a lot of folks here that are able to help you with that, if it is in deed possible. Please post the brand and model of both your television and stereo.
1. Use the analog audio or headphone out of the RCA if it has them.
2. Use the optical audio output with a DAC to convert it to analog for the Sony.
3. If the TV doesn't have any audio outputs you can't connect it to the Sony without modifying the set.