What is calculated
The Sun is the apparent position of our star as seen from Earth. In this chart its sidereal longitude is calculated before a sign or nakshatra is assigned.
Sun is displayed by sidereal sign, degree within the sign, whole-sign house, nakshatra, and pada. The beta does not turn this coordinate into a predictive reading.
How to inspect the result
Begin with the birth details and calculation method, then read the placement table. A sign label can change near a 30° boundary when the input or ayanamsa changes slightly.
The South Indian chart shows the same sign and house relationship visually. It is a different presentation of the calculated data, not a separate calculation.