There is a certain course of action in Vedic astrology to determine the Mahadasha period. Based on it, 3 Nakshatras are proportioned out to every Earth, that makes the amount of Nakshatras rely to 27 for the many 9 planets. So, the Mahadasha of any planet depends upon the situation https://www.youtube.com/shorts/oUsNAkX7h9w