Vishakha is nakshatra number 16 of the 27 lunar mansions in Vedic astrology, spanning 200.00° of the zodiac in 13°20' steps. Its planetary lord is Jupiter and its presiding deity is Indra-Agni.
The Moon's position in Vishakha at birth shapes the Vimshottari Mahadasha sequence — a Vishakha birth begins life in the Jupiter 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 Vishakha is your janma nakshatra, and the Panchang to see exactly when the Moon transits Vishakha on any date.