Out of the ten poruthams prescribed by South Indian Astrological rules, it is called as "Yoni Porutham".
Hindu Rashi/ Nakshatra Matching
In South India, Yoni Matching (Porutham) of the bride and groom. It is mostly done when the marriages are arranged by the families of the boy and the girl.
Importance of Yoni Porutham
Yoni Porutham is important because this is the porutham which helps in determining the sexual compatibility between the couple after marriage and forms the basis of the marriage as this is the sole aim in a man and a woman coming together while living together in harmony is secondary.
Yoni porutham should be mapped out for both the girl and the boy and not just for the girl because it is accountable for the physical compatibility of the married couple. There is no fixed parameter which says that a particular zodiac star is compatible physically with the other's star (nakshatra).
Yoni porutham can only say about the incompatibility of the stars in question, not about their compatibility as is evident in daily life where the husband and the wife are not always at the same emotional and physical relationship with one another; on one occasion they may be compatible but on other occasion they may not be. Therefore, it is an assumption that if one nakshatra is incompatible, the other nakshatra may or may not be compatible.
Some married couples are found never to be at a satisfactory compatibility with each other, either physically or emotionally. The yoni porutham is applicable for such relationships. Here, the human behaviour during sexual relations is taken into consideration and accordingly the incompatibility is charted which when looked at conversely, shows what is compatible.
Nakshatra - Yoni
1. Ashwini - Male horse
2. Bharani - Male Elephant
3. Rohini - Male Snake (cobra)
4. Thiruvathirai - Male Dog
5. Poosam - Male Goat
6. Aayilyam - Male Cat
7. Maham - Male Rat (Mouse)
8. Uthiram - Male Ox
9. Chithirai - Male Tiger
10. Swathi - Male buffalo
11. Kettai - Male Deer
12. Pooradam - Male Monkey
13. Poorathathi - Male Lion
14. Karthikai - Female Goat
15. Mrigashrish - Female Elephant
16. Punarpoosam - Female Cat
17. Pooram - Female Tiger
18. Hastham - Female buffalo
19. Visakam - Female Tiger
20. Anusham - Female Deer
21. Moolam - Female Dog
22. Uthiradam - Female Cow
23. Thiruvonam - Female Monkey
24. Avittam - Female Lion
25. Sathayam - Female Monkey
26. Uthiratathi - Female Cow
27. Revathi - Female Elephant
While considering yoni match if boy has Male Yoni and girl has Female yoni the match is perfect or uthamam.
If both boy and girl has male yoni the match is mathimam.
Otherwise the match is Athamam or no match.
Yoni match is considered for physical compatibility or sexual compatibility.