This is the diagram of Manda Kriya, Reduction to the Heliocentric Coordinate System, given by the equation R e Sin M, where e is eccentricity, R is the Radius of the Circle, M is the Anomaly.
The Manda Anomaly is found out by subtracting Aphelion, Mandoccha from the Mean Longitude.
Mean Longitude - Aphelion = Manda Anomaly.
R = 360/ 2 Pi or 180/Pi or 57.3*60*60 = 206265 seconds or Vikalas.
This amount thus got is added to the mean longitude if ML > 180 and deducted if ML < 180.
The Kerala astronomers predate their Western counterparts, particularly Kepler and Laplace by centuries. In his Thesis " The Model of Planetary Motion in the works of the Kerala astronomers", Prof Ramasubramaniam, Physics Professor, Madurai University observes " In conclusion, it may be noted that there is a vast literature on astronomy, including mathematics, both in Sanskrit and Malayalam produced by the Kerala School during the period 14-19th century. Only a fraction of it has been published and so far only a few studies of these texts have appeared ".
The era and the astronomer
Parameswara - 15th century
Neelakanta - 16th century