virtualbox.org

appliance is stuck after showing ramdisk is loading
your help will be highly appreciated

Not stuck, just slow.

00:00:11.160014 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:11.324494 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

Hyper-v enabled. Read posts #2 and later of FAQ: I have a 64bit host, but can't install 64bit guests.

what should i do know

Mustafa_Ahmed wrote:what should i do know

First, acknowledge that you saw and acted on Mpack's advice, and state the result of the changes recommended.

How did Mpack's suggestions work?

followed steps and selected Hyper-v enabled in system settings of Vbox

Mustafa_Ahmed wrote:selected Hyper-v enabled in system settings of Vbox

If you are refering to the "Paravirtualization interface", then changing this should not be necessary and was not called for in the 64-bits tutorial. That setting is only to enable modern operating systems that are programmed to know they might be in a virtual machine to have communication with the host computer's operating system and virtualizer.

Change the Paravirtualization interface back to its old setting.

If "followed steps" means your guest is now booting better, then good.

The "kernel panic" error with "timer does not work" is not a Virtualbox problem. Solve this as if your Kali guest were a real PC. See what Kali's forums and help can tell you. In fact the error tells you what to do. Just follow the instructions in your screenshot.

Though this is not a Virtualbox problem, you might try changing the "Enable I/O APIC" setting in Sytem > Motherboard tab.

in the same way ubuntu is also stucking at blackscreen

By "followed steps" Scott means that you clicked on the link I gave you, and you followed the instructions found there.

The paravirtualization API setting is not relevant to this discussion, and I'm pretty sure Scott didn't say it was.