Krittika is nakshatra number 3 of the 27 lunar mansions in Vedic astrology, spanning 26.67° of the zodiac in 13°20' steps. Its planetary lord is Sun and its presiding deity is Agni.
The Moon's position in Krittika at birth shapes the Vimshottari Mahadasha sequence — a Krittika birth begins life in the Sun mahadasha, with the balance of that period decided by how far the Moon had travelled through the nakshatra.
Use the free Kundli generator to find whether Krittika is your janma nakshatra, and the Panchang to see exactly when the Moon transits Krittika on any date.