so my Denominator will be 5 :
/ip firewall mangle
add action=mark-connection chain=prerouting connection-mark=no-mark disabled=no dst-address-type=!local in-interface=ether5 new-connection-mark=WAN1 passthrough=yes per-connection-classifier=both-addresses:5/0
add action=mark-connection chain=prerouting connection-mark=no-mark disabled=no dst-address-type=!local in-interface=ether5 new-connection-mark=WAN2 passthrough=yes per-connection-classifier=both-addresses:5/1
add action=mark-connection chain=prerouting connection-mark=no-mark disabled=no dst-address-type=!local in-interface=ether5 new-connection-mark=WAN1 passthrough=yes per-connection-classifier=both-addresses:5/2
add action=mark-connection chain=prerouting connection-mark=no-mark disabled=no dst-address-type=!local in-interface=ether5 new-connection-mark=WAN2 passthrough=yes per-connection-classifier=both-addresses:5/3
add action=mark-connection chain=prerouting connection-mark=no-mark disabled=no dst-address-type=!local in-interface=ether5 new-connection-mark=WAN2 passthrough=yes per-connection-classifier=both-addresses:5/4
is this rule right or not ?
Yes, that's right. Have you given it a try?