3-6-1 right tactics ??

[Medo zalata]

I want to test this formation this season what do you think ??
Is this defensive counter formation or attacking ??
What are best tactics with it??
I saw someone against a friend of mine
4-3-3 (4-5 stars) against this formation (2-3 stars except gk and st )
However my friend could win really hard with a goal at the last minute although he must have been favourite and the possession was nearly equal 51-49