We have Sony MHC-GX450 sound system in our home which has 3 CD disk and 2 cassette spaces which is outdated. So I don't want to those speakers to go waste without using. Because of which I'm finding the help to connect those speakers to new Sony Bravia android TV. And I don't know how to do that.
Please help me out with this problem.
Your old system has a game audio input jack on the front.
Most Sony TVs have a hybrid headphone/line level audio out. You can use that to get audio from the TV to the sound system. Check the TV manual on how to use that output.