Can a guy from dhananjaya gotra marry a girl from same gotra with different surname?

In Hindu culture, marriage between individuals of the same gotra is traditionally prohibited as they are believed to be blood relatives. However, in certain regional and community-specific customs, this restriction may vary. In the scenario you mentioned, if the individuals are from the same gotra but have different surnames, it is important to consult with a knowledgeable elder or priest familiar with the specific customs and traditions of their community to determine if such a marriage is permissible.