Create a NAT Network using VBoxManage
utility
Open a command prompt (cmd
or terminal if you are on Linux/Mac)
## Check existing NAT Networks
$ VBoxManage list natnetworks
## Create a NAT Network
$ VBoxManage natnetwork add --netname NATNetwork101 --network "192.168.10.0/24" --enable
## Check the NAT Network
$ VBoxManage list natnetworks
NetworkName: NATNetwork101
IP: 192.168.10.1
Network: 192.168.10.0/24
IPv6 Enabled: No
IPv6 Prefix: fd17:625c:f037:2::/64
DHCP Enabled: Yes
Enabled: Yes
loopback mappings (ipv4)
127.0.0.1=2
## Enable or Disable DHCP for the network (on or off)
$ VBoxManage natnetwork modify --netname NATNetwork101 --dhcp on
## Start the NAT service
$ VBoxManage natnetwork start --netname NATNetwork101
## Enable Port Forwarding to connect to the VMs
## Forward localhost port 1022 to 192.168.10.5:22 (eg: SSH)
$ VBoxManage natnetwork modify --netname NATNetwork101 \
--port-forward-4 "ssh:tcp:[]:1022:[192.168.10.5]:22"
## If you need to remove the NAT Network
$ VBoxManage natnetwork remove --netname NATNetwork101
Use NAT Network for Virtual Machines
Once you have created NAT Network, assign the same for the VM Network.

Also you can use VBoxManage
utility for the same if you are a command line hero.
## Assign NAT Network to a VM
$ VBoxManage modifyvm UbuntuVM --nic1 NATNetwork101
How To Create And Use NAT Network In VirtualBox