Vedic astrology defines twenty-seven Nakshatras. Abhijit Nakshatra is not considered while counting 27 Nakshatras.
Following 11 Nakshatras are considered Shubh for marriage.
Marriage conducted during these Nakshatras bestows bride and bridegroom with sons, grandsons, wealth, reciprocal sympathy, mutual affection and happiness.
However, the first quarter of Magha/Makha and Moola and the last quarter of Revati are inauspicious and they should be rejected. According to Jyotirnibhandha, these periods inflict death to the couple.
Many astrologers avoid Uttara Phalguni as it is believed that Lord Rama and Goddess Sita were married during Uttara Phalguni and they had a lot of difficulties and miseries in their married life.