my device supports wol
Sure, once you allow the traffic.
how do i enable this? can u kindly point me to a tutorial?
You'll need to provide a lot more details (what device, what kind of internet connections, etc.) before anyone can answer you.
Just in general, one would usually install luci-app-wol on the router and then use a VPN to connect to the router, to access luci-app-wol and wake up the systems behind the router - yes, there are other ways to accomplish this, but that are horrible from a security point of view.
WoL can't work for the router itself.
…but again, we're just guessing about what you might want to know.