Usually there are adapters that have the A/V cables with a cord that can go Ito your galaxy- also idk for sure but I believe there is a docking station that goes from your samsung to the HDMI cable. You can find them online.
You can watch Netflix movies on your TV from your Samsung Galaxy S3 phone using a USB cable. However, you need an HDMI USB cable for you to be able to stream Netflix from your smartphone to the TV. You will also be required to have the Netflix app on your phone. Check out http://www.ehow.com/how_8366146_stream-netflix-tv-hdmi-cables.html.