Question about Samsung Hw-Ms650

The Soundbar is compatible with your TV, you just need to use the OPTICAL audio cable supplied with the Soundbar. The bracket is also compatible.

I personally use the soundbar with the bracket you mentioned and a Samsung UE65KS8080 and everything fits perfectly.

Good day
It is better to use an HDMI cable for the audio connection. To do this, use the HDMI 3 ARC connection of the TV and the HDMI ARC of the Soundbar. If you have an additional HDMI player later on, you can connect this video signal via the Soundbar, which then forwards the signal to the TV.