Rashi and nakshatra
The 27 Nakshatras spread across the 12 zodiac signs lie entirely within a sign, whereas certain stars overlap in two zodiac signs.
Each nakshatra has its own ruling deity and powers, which play a major role in deciding the characteristics of an individual. Everyone born on this earth has nakshatra and rashi based on date of birth and placement of moon decide the rashi and nakshatra.
These nakshatra and rashi are broadly classified under the three heads of Deva (divine), Nara (human) and Rakshasa (Demonic). Farther, they are subdivided by their gender and Varna (cast), and are also ascribed with qualities such as colour, presiding deity, merits and ruler ship of body parts, planets etc.
The effects of a particular planet is studied with Birth nakshtra and rashi and its pada born in mind. Indians through ages have been taking into account these Nakshatras for determining the auspicious dates and Muhurtha (moment) for any cultural or religious event including marriage. The role of Nakshatras and their respective Padas in predictive astrology is unique to Indian astrology.