I have redirected upload traffic to imq0 by using IMQ in the PREROUTING chain and download traffic in the POSTROUTING chain to imq1.

Upload traffic --> -i br-lan+tun --> imq0

Download traffic --> -o br-lan+tun --> imq1

IMQ module is set to before NAT in PREROUTING and after NAT in POSTROUTING.

So on which interface should I enable the "nat" option, imq0, imq1, both or none?

Thanks.