While matching horoscopes for a marriage under the Koota matching system, the birth stars in which the Moon is placed at the time of birth, called Janma Nakshatra, in which the bride and bridegroom are born, are analyzed and matched for various compatibility factors. One of them is the Ganas of the nakshatra.
All the 27 Nakshatras come under 3 groups. They are Deva Gana, Manushyagana and Rakshasagana.
If both bride and bridegroom are born in the same Gana then the matching is supposed to be the best.
So the best combination is Deva-Deva, Manushya – Manushya and Rakshasa-Rakshasa.
In the Gana matching this combination gets 4 out of 4 points. The next best is between Deva-Manushya and Manushya-Rakshasa. This gets a score of 2 out of 4 points.
The last and worst combination is Deva-Rakshasa which gets a score of 0 out of 4 points.
This is as per the detailed South Indian Dasha Koota matching system.
In the North Indian Ashtakoota Matching system the Gana matching is allotted 6 points and you get either 6, 3 or 0.
Unfortunately too much importance is given to this Gana matching because of two reasons. Firstly as in case of Mangala Dosha, the person born under Rakshasagana has more confident and aggressive tendencies and hence this becomes a major taboo for a girl.
Secondly a good Gana matching enhances prosperity.
However, what the average public and even a lot of astrologers fail to take into account is the fact that, out of the total 36 point Koota matching, the Gana matching carries only 3 points.
What is even more important is the fact that out of the 9 planets we are only taking into account the Ganas of the stars in which the Moon is placed at birth and totally ignoring the Ganas of the stars in which the balanced 8 planets are placed.
If someone still has doubts on this, they should understand that people born under Deva Gana have lots of patience and are soft natured.
People born under Manushya Gana have patience but they can be aggressive at times.
People born under Rakshasa Gana are mostly short tempered and aggressive.
So, its better to marry someone in same gana to match qualities.