The sidereal coordinate method takes into consideration the ayanamsa, ayan indicating "transit' or 'movement', and amsa indicating 'tiny part', i.e. motion of equinoxes in little pieces. It is unclear when Indians became mindful of the precession of the equinoxes, but Bhāskara II's 12th-century treatise Siddhanta Shiromani offers equations for measurement https://astrodienst09416.digiblogbox.com/43443470/the-best-side-of-zodiac