Short answer: Yes. A Jain can marry someone from another religion.

Key points to keep in mind:

• Different Jain communities (Digambar and Śvetāmbara) may have slightly different norms, but interfaith marriage is generally allowed in Jain tradition.
• Many Jain families want the non-Jain partner to respect and participate in Jain practices, and there’s often discussion about how children will be raised (which religion or combination of practices).
• The wedding itself can be conducted with Jain rituals or in a civil ceremony, depending on family preferences. What matters in Jain dharma is the sincerity, non-violence, and mutual respect in the relationship.

If you’d like, I can point you to specific Jain Knowledge resources that discuss Jain marriage customs and how to handle interfaith arrangements.