Thanks @openaspace . i am posting the final configuration for those who may have the same problem like us. thank you.
auto lo
iface lo inet loopback
iface lo inet6 loopback
iface enp6s0 inet manual #the original interface
auto vmbr0
iface vmbr0 inet static
address 178.63.xx.35/32
gateway 178.63.xx.1
pointopoint 178.63.xx.1
bridge-ports enp6s0
bridge-stp off
bridge-fd 0
up ip route add 178.63.xx.47/32 via 178.63.xx.1 dev vmbr0
iface vmbr0 inet6 static
address 2a01:4f8:121:xx::2
netmask 64
gateway fe80::1
auto vmbr1
iface vmbr1 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094
auto lo
iface lo inet loopback
iface lo inet6 loopback
iface enp6s0 inet manual #the original interface
auto vmbr0
iface vmbr0 inet static
address 178.63.xx.35/32
gateway 178.63.xx.1
pointopoint 178.63.xx.1
bridge-ports enp6s0
bridge-stp off
bridge-fd 0
up ip route add 178.63.xx.47/32 via 178.63.xx.1 dev vmbr0
iface vmbr0 inet6 static
address 2a01:4f8:121:xx::2
netmask 64
gateway fe80::1
auto vmbr1
iface vmbr1 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094