In Jain Dharma, marriage is generally guided by family tradition, gotra rules, and community custom, not by a universal scriptural rule about one surname alone.

If “Chajjer” means the same family name/surname, then:

• Same surname does not automatically mean marriage is forbidden in every Jain community.
• But if both belong to the same gotra, close blood relation, or a community that treats that lineage as prohibited, then marriage is usually not accepted.
• The exact rule can differ between Digambar and Shwetambar communities and also by local tradition.

So the correct answer is: it depends on gotra and family lineage, not just the surname “Chajjer.”