You can't find it on the map, but once it's on click on the orange bar that shows name of current event and it will have ''participate'' *on that will teleport you to it, this works for almost every event, Sage War, Matsuri and etc.

yeah, its located where team instance, and sage battlefield would be, if you havent seen those, then below your stamina and and lvl etc there is the orange bar that shows you the events and what day they are held.

9 tails can be found during the event 20:10-21:00 Mon,Tues,Thurs,Fri,Sun. Check the left bar "Nine tails invasion on progress" to join the event, then click participate. Keep 30 coupons and 30k coins for anbu/support too to increase your damage on 9 tails.