It looks to be part of a full Age of Sigmar themed Realm of Battle 6-plate set.
If you take out your Age of Sigmar softcover 96pg book and turn to the missions section, look closely at the board the mission objectives are drawn on:
We get this:
Now ignore the text and dark outlined mission objectives and look at the tiles behind. Then notice that pattern of what makes up the 6 tile set:
About Rob Baer: Founder, Publisher, & Managing Editor of Spikey Bits, the leading tabletop gaming news website focused on the hobby side of wargaming and miniatures.
Rob also co-founded and currently hosts the Long War Podcast, which has over 350 episodes and focuses on tabletop miniatures gaming, specializing in Warhammer 40k. and spent six years writing for Bell of LostSouls.
With over 30 years of experience in retail and distribution, Rob knows all the products and exactly which ones are the best. As a member of GAMA (Game Manufacturers Association), he advocates for gaming stores and manufacturers in these difficult times, always looking for the next big thing to feature for the miniatures hobby, helping everyone to provide the value consumers want.
While he’s played every edition of Warhammer 40k and Warhammer Fantasy (since 5th Edition) and has been hobbying on miniatures since the 1980s, Titans of all sizes will always be his favorite! It’s even rumored that his hobby vault rivals the Solemnance Galleries, containing rulebooks filled with lore from editions long past, ancient packs of black-bordered Magic Cards, and models made of both pewter and resin.