Dangerous Machine Type-6 is a Continuous Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Dangerous Machine Type-6 is Unlimited.
YGOPRODeck lists Dangerous Machine Type-6 for these formats: OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Dangerous Machine Type-6 appears in Duelist League 3 participation cards (DL12-EN016) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Dangerous Machine Type-6 is about $0.48 on Cardmarket (prices change frequently).
