How to connect Linux Mint Desk Top PC with HDMI to Samsung TV
 

I have a Desk Top PC with Linux Mint 18 sonya Cinnamon 64 bit. I wish to connect the same to Samsung TV. And I have already connected the HDMI cable to PC and the TV. I am unable to get the display in the TV screen except the PC's background screen. I have also installed the ARanR in the computer. Please help what additional things to be done.

Hard to say, since you don't tell us anything about your hardware. Without knowing what kind of TV, whether you have the HDMI input selected, or (more importantly) what kind of PC and graphics hardware you're using, we can't even begin to guess. And your post is fairly confusing...you say " I am unable to get the display in the TV screen except the PC's background screen"...which implies that you ARE able to get a picture from your PC to the TV.

Is it working or not? What is the actual problem?

You have to make the TV your primary screen on the computer. You can do that with gnome-control-center. Right now it's configured as a secondary screen with just the wallpaper, sort of like just some extra screen space.