I agree, just because you have a pair of Red/White RCA-style connectors does not mean they are Outputs. If they are outputs they will be labeled as out put, or with a symbol of a Circle with an Arrow point OUT.
In the owner's manual for the TV, either there in your hand or on-line, you should be able to look and see if there are Analog Audio Outs. In some cases, this may be as simply as a Headphone out.
Also, you many need to go into your TV menus and check the Audio Settings. If nothing else, once you get sound in your stereo, you will probably want to turn the TV speakers off.
There are three potential source of sound output from a TV.
1.) The Headphone out - For sound quality this is OK, but not ideal. However, it does have the advantage that when you adjust the volume on the TV, the volume of the signal being sent to the Amp also changes. Meaning you can continue to use the TV remote control to control the volume.
This is the lowest cost method.
2.) Analog Audio Out - Most new TV do not have this feature, though a few do. In some cases, the Audio Out is found in the SCART connector, and requires a very low cost adapter (£3 to £5).
In some case, there is an output on the back of the TV that looks like a headphone out, and may contain both the Analog (which is what you are looking for) and the Optical Digital Audio Out signal. Which you get depends on the type of cable you plug in. I'll discuss Optical Digital Audio Out later.
Or the Audio Out may be in the from of a Red/White pair of RCA-Phono style connectors.
Just one small problem, the Analog (meaning not digital) Audio Out is usually FIXED, meaning the output signal does not change with changed to the volume on the TV. Rather, you use the Volume Control on the Remote Control of the amp. There are a rare few TV in which the Audio Out can be switched between FIXED and VARIABLE. Variable is just what it implies, when the TV sound level changes, the output signal to the amp changes. But the most common and most likely is FIXED, so rather that the TV volume, you control what you hear at the amp.
This probably has the best sound quality of the Analog out options.
3.) Optical Digital Audio Out - This one gets complicated, because you need a means to converts a series of number to the voltage equivalent. Digital music needs to be converted to Analog music, and this is done with a DAC (Digital to Analog Converter). Just one small problem DACs cost money. If you care about sound quality then a good basic DAC is going to cost about £150, though you can get a very basic single purpose one for about £50.
The Digital Optical Out of the TV plugs into the Optical input of the DAC. The Analog output of the DAC plugs into the Analog (AUX, TAPE, similar) of the Stereo Amp.
Now this assumes your TV is relatively recent, say within the last decade. Virtually all modern TVs have a Optical Digital Audio Out. Because what is coming out is just a series of digital number, there is no way to control the volume, so again FIXED level output. You need to control the volume with the amp.
So, those are your options.
If you have a Headphone out, and you want the simplest operation with virtually no additional cost, then this is probably a workable choice.
If you can determine that you TV has a standard Analog Audio Out, this is a bit better choice.
If you are stuck with just the Optical Audio Out, then it means some money out of your pocket for a DAC. How much or how little money is based on your budget and your requirements.
Hopefully that helps.
Steve/bluewizard