The permissibility of dating or marrying a "god brother" depends on cultural and religious beliefs, as well as legal regulations in different parts of the world. In some cultures and religions, the term "god brother" may refer to individuals who are not blood-related but share a spiritual or religious bond due to being part of the same religious community or having the same godparent.
In many societies, it is generally acceptable for unrelated individuals who have a godbrother/godsister relationship to date and marry, as they are not considered blood relatives. Legally, there are typically no restrictions against such relationships.
However, as with any relationship, it is essential to consider the cultural, religious, and legal context of the specific situation. Different societies and belief systems may have various norms and practices regarding dating and marriage, so it is best to be aware of and respect those norms when making such decisions. If there are any doubts or concerns, consulting with trusted family members, religious leaders, or legal advisors can be helpful.