LEGO® Minifigures™ Series 6 were introduced on January 9, 2012. Collection includes: Roman Soldier, Highland Battler, Minotaur, Bandit, Classic Alien, Genie, Leprechaun, Intergalactic Girl, Butcher, Mechanic, Skater Girl, Surgeon, Sleepyhead, Clockwork Robot, Lady Liberty and Flamenco Dancer.
The idea behind collectable Minifigures™ was that each minifigure come in a sealed bag, so you never knew which minifigure you might get. You can reed more details on Series 1, Series 2, Series 3, Series 4 and Series 5.
Detailed information can be found on LEGO® website here.
Although released in 2012, not available any more You can still try to find them on eBay.
Some more information on this series can be found on Brickipedia.
Below you can find photos of all Minifigures in this collection:
