Effect of Kuja Dosha : When present in a horoscope, the dosha results in destruction of the spouse or adversely effects the marital relation.
But when both the Boy and Girl have equal Kuja Dosha then the marraige can be performed as the Kuja Dosha is said to be cancelled
Who will not have Kuja Dosha : People with their Janma Lagna in Karka, Simha, Mesha, Vrischika, Dhanu, Meena, Makara will not have Kuja Dosha . And People born in the nakshatras of Aswini, Mrigasira, Punarvasu, Pushyami, Aslesha, Uttara, Swati, Anuradha, Poorvashadha, Uttarashadha, Sravana, Uttarabhadrapada and Revati also will not have Kuja Dosha.
Other Exceptions to Kuja Dosha due to certain placements of Planets :
1. If Kuja and Chandra or Kuja and Guru are conjoined in a horoscope
2. When the Janma lagna is Kanya or Mesha and Kuja is in the 2nd house
3. When a strong Benefic planet is in the 9th house
4.For natives with janma lagna in Tula or Vrishabha and when Kuja is in 12 th bhava
5.For natives with Janma Lagna in Mesha or Vrischika and when Kuja is in 4th Bhava
6.For natives with Janma Lagna in Makara,Karkataka and when Kuja is in the 7th Bhava
7.For natives with Janma Lagna in Dhanu or Meena and when Kuja is in 8th house
8.In a Female horoscope when Poorna Chandra is in 2nd house along with one of Budha ,Guru or Sukra
9.When Saturn is placed in Lagna or in one of 4,9,12 bhavas
10.In both Male and Female horoscopes when malefic planets are in 2 or 7 th bhavas
11.when both male and female has equal dosha or when one has Kuja dosha from lagna and the other has Kuja dosha from Chandra and Sukra
In all the above instances listed Kuja Dosha is not said to be present.