Nitro Unit is a Equip 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, Nitro Unit is Unlimited.
YGOPRODeck lists Nitro Unit for these formats: GOAT, OCG GOAT, Duel Links, Edison, TCG, OCG, Master Duel.
A listed print of Nitro Unit appears in Dark Revelation Volume 3 (DR3-EN226) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Nitro Unit is about $0.13 on Cardmarket (prices change frequently).
