5.1 through home theater setup?

I have a XBox 360, Sharp BD-HP20U Blu Ray player, LG 60PC1D TV and a RCA RT2770 Theater System. My question is that If I have Composite Video and Audio cables running from my Blu Ray player to my TV, & HDMI running from my XBox 360 and Cable Box to my TV. Will I still get 5.1 through my surround sound If I have a Digital Optical Cable running from TV to my RCA Theater System?