Is it permissible for a Christian woman in India to marry her maternal grandmother’s brother’s son? Could such a marriage be legally challenged by others?

In India, marriage between a woman and her maternal grandmother’s brother’s son is considered consanguineous and is prohibited under the Hindu Marriage Act, 1955. While this law applies to Hindus, Christians can choose to be governed by their personal law or the Special Marriage Act, which also prohibits marriage between close relatives. Such a marriage could be challenged on grounds of prohibited degrees of relationship.