In Jainism, there is no universal or fixed “kuldevta” (family deity) like in some Hindu traditions. Jains traditionally focus on the Tirthankaras as the primary spiritual guides, and many also revere Yaksha/Yakshini (guardian spirits) for personal or local temple practices. The idea of a specific kuldevta for a place or for all people of a family is not a standard Jain doctrine.

If a Jain family in Buchs (or anywhere) follows a local tradition, their personal or family deity would be a local choice and not part of a canonical Jain system. For precise practice, it’s best to ask the local Jain community or temple in your area, as customs can vary by region and community.