Gana Dosh occurs when the Gana of the bride and groom are incompatible in Kundali matching, potentially causing conflicts and lack of harmony in marriage. There are three types of Gana and when there is matching between Manushya Gana and Rakasha Gana, we see Gana dosha is there. You should do Grah Milan which is matching of all planets to check how strong is your charts for marriage.
General remedies for Gana Dosh include performing Gana Dosh Nivaran Puja or Graha Shanti Puja under the guidance of a learned Brahmin. Chanting Maha Mrityunjaya Mantra or Gayatri Mantra daily helps reduce malefic effects. Offering prayers to Lord Shiva and Goddess Parvati strengthens marital harmony. Donating clothes, food, or money to the poor on Mondays and observing fasts can also be beneficial.