Mithuna (Gemini) and Vrischika (Scorpio) sit sixth and eighth from each other in the zodiac, and that placement shapes the rashi-level checks in both Sinhala porondam and Tamil porutham. This page explains those results for each direction, and why the two birth stars matter far more than the signs alone.
Which rashi is being matched here?
The rashi used in porondam and porutham is the moon sign (chandra rashi), the sign the Moon occupied at birth in the sidereal zodiac used in Sri Lanka. It is not the sun sign printed in newspaper horoscopes, so someone who calls themselves a Gemini may have a quite different moon sign.
Several checks depend on the rashi alone: the rashi count (how many signs apart the two moon signs are, counted from the bride's sign to the groom's), whether the two rashi lords are friends, and vashya, a traditional measure of mutual attraction between signs. Because counting starts from the bride's sign, results can differ depending on who holds which sign.
What happens when the bride is Mithuna and the groom Vrischika?
Counting from Mithuna to Vrischika gives 6. In the Sinhala system, rashi, rashyadhipathi and vashya are all not obtained for this direction, and the Tamil system gives the same picture: rasi, rasi adhipathi and vasya are all not obtained.
The rashi lords are Mercury for Mithuna and Mars for Vrischika. They are not friends: the relationship is neutral in one direction and hostile in the other, which is why the lord check is not obtained. These are only three items among many, though, and they say nothing yet about the couple's birth stars, which carry most of the weight in a full match.
What changes when the bride is Vrischika and the groom Mithuna?
With the signs reversed, the count from Vrischika to Mithuna is 8. Here the Sinhala rashi item is partly obtained, a small difference from the other direction, while rashyadhipathi and vashya remain not obtained.
In the Tamil system, rasi, rasi adhipathi and vasya are all not obtained in this direction too. The lords are still Mars and Mercury, and their relationship is unchanged: neutral one way and hostile the other, so they do not count as friends. The Sinhala partial result on rashi is the only rashi-level change, but as the next section shows, the star-level outcomes shift much more noticeably between the two directions.
Why do the birth stars decide the real match?
Each moon sign spans parts of three nakshatras, giving 81 possible star-quarter combinations for a couple in these two signs. The calculator's figures show how varied those combinations are. In both directions, none reach 8 of 10 Tamil porutham, about 75% fall into the weaker Tamil band, and about 4% involve a Tamil rajju clash.
The Sinhala picture differs sharply: excluding the weekday check, about 10% of combinations pass porondam with a Mithuna bride, against about 62% with a Vrischika bride. For any real couple, enter full birth details in the calculator, and for marriage decisions consult a family astrologer.
Read the Mithuna horoscope and the Vrischika horoscope, or check two exact birth charts with the porondam calculator.