Dear Stuti,
nadi is the most important Koot in the Guna milan and that is why it has maximum number that is 8 score in the Ashtkoot Guna milan. Having Nadi dosha is never good. It indicates major problems in the relationship. Nadi is the Pulse and Nerves energy. It is the ability to produce healthy children. Definitely Nadi dosha indicates health issues to the self and problems to the children can be there. Therefore generally when Nadi dosha is there, no one will recommend marriage, unless Nadi dosha gets Cancelled.
Blessings,
Navneet Khanna
Astrologer