In Jain Dharma, there is no specific mantra to “move into a nuclear family.” Jain practice distinguishes between the life of a household (shrāvaka/shrāvikā) and the renounced path. Marriage and family life are social duties guided by dharma, conduct, and harmony within the household, not by a particular mantra to change one’s family structure.

If you’re seeking blessings for a harmonious family or for auspicious beginnings in a marriage, commonly people turn to general Jain prayers that honor the Tirthankaras and cultivate virtuous conduct, such as the Namokar Mantra. There are also traditional prayers and stotras recited for auspicious occasions and to seek peaceful, ethical living within the family. Do note that the exact practices and preferred stotras can differ between Digambar and Śvetambar traditions.

If you’d like, I can provide concise, authentic Jain stotras or verses that are appropriate for auspicious家庭 events or marital harmony, along with their Jain-dharma meanings.