Mrigashira is nakshatra number 5 of the 27 lunar mansions in Vedic astrology, spanning 53.33° of the zodiac in 13°20' steps. Its planetary lord is Mars and its presiding deity is Soma.
The Moon's position in Mrigashira at birth shapes the Vimshottari Mahadasha sequence — a Mrigashira birth begins life in the Mars 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 Mrigashira is your janma nakshatra, and the Panchang to see exactly when the Moon transits Mrigashira on any date.