In Jainism, there is no specific mantra exclusively prescribed for marriage as seen in some other traditions. However, Jains often recite auspicious prayers and seek blessings from the Tirthankaras for any significant occasion, including marriage.

A common and highly revered mantra in Jainism is the Navkar Mantra (Namokar Mantra). It is considered the most powerful and auspicious mantra, suitable for all occasions. Jains may recite this mantra before beginning any important event, including a marriage ceremony, to seek blessings for happiness, peace, and spiritual progress.

Navkar Mantra:

णमो अरिहंताणं। णमो सिद्धाणं। णमो आयरियाणं। णमो उवज्झायाणं। णमो लोए सव्व साहूणं॥

This mantra venerates the Panch Parameshti (five supreme beings) and is believed to purify the mind and environment.

For a marriage, you may recite the Navkar Mantra to invoke blessings for a harmonious and virtuous married life in accordance with Jain principles. Additionally, Jain priests may perform special prayers or rituals (puja) seeking the well-being of the couple, but these are not fixed mantras for marriage specifically.