In Jainism there is no fixed rule that assigns a specific surname or gotra when someone joins the faith.

• Surname: As a lay Jain, you usually keep your family surname (your existing last name) and you may also use a Jain community or business surname that comes from your family background. Jain monks and nuns normally renounce family ties, and their names reflect their monastic status, not a caste or gotra. There is no universal Jain-only surname you must adopt.

• Gotra: The traditional gotra system is a Hindu āshrama/lineage concept. Jain tradition does not use gotra in the same way. Most Jains do not follow a formal gotra designation. If your family has a gotra in a Hindu context, it isn’t a required or central part of being a Jain.

• Digambar vs. Shwetambar: Both major Jain traditions focus on ethics, vows, and spiritual practice rather than genealogical identifiers. Any subtle, family-specific naming customs (if they exist) would come from local community traditions rather than canonical Jain rules.

If you’re seeking exact guidance for a specific community or region, it’s best to consult a local Jain learned person or a temple priest from the tradition you’re joining, since practices can vary by community.