I connected my TV who had Netflix with my Yamaha home theater unit with an optical cable. However I cannot get Netflix' 5.1 so

[phytosn]

Netflix 5.1 through optical cable on to Yamaha home theater

 

[americanaudiophile]

Do you get 5.1 on other sources?
If not then check the TV audio type menu. Change the audio type.
If you do then try changing your audio setting in the Netflix account.
Make sure that the surround mode on the receiver is set correctly too.