I just want to record the 4k video stream from the camera NOT want to play it on Raspberry. Can raspberry pi do this using vlc ?
The official Raspberry Pi Camera does not support 4K, so No - If that is what you wanted.
If you have a USB 2.0 4K camera1 that can dump encoded data then yes. As long as the driver is picked up you can use any software you like to capture the stream, even UV4L userspace driver.
I do not think USB 2.0 has enough bandwidth for RAW2 capture but possibly if the camera encodes it for you with h.2653 it should be fine. You just save the stream to your drive.
1 - Something like the PanaCast Panoramic 4K Resolution USB Camera - But Linux compatibility may be limited
2 - 4K at 24fps RAW - 4096 x 2304 x 24 x 12 / 8 / 1024 / 1024 = 324MB/s
3 - https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding