Vivo V5s comes with latest Android 6.0 Marshmallow OS which has got Vivo's patented FunTouch 3.0 skin layer. Since the device is newly launched, we do not expect that company will release the new software update immediately.
No. You cannot record 4k videos.
Yes, you can play FM Radio on Vivo V5s.
Yes, Vivo V5s has Sony IMX376 Exmor RS sensor for the selfie camera.