Need to separate entities from methods?

Question

ASP.NET

ASP.NET MVC application. Infrastructure layer.
There is a ConcreteRepository repository which has a GetConcreteData(inputData) method. Inside it is sending a PostRequest (url) request that receives data in JSON format from the microservice and maps this Json into an object of DataJson type.
Example:

public class ConcreteRepository
{
   public ModelDto GetConcreteData(Model inputData)
   {
       var result = PostRequest<DataJson>(url);
       ...
       return resultDto;
    }
}
public class DataJson
{
   public int _id {get;set;}
   public string _name {get;set;}
   ...
}

The question is: Where is the best place to store DataJson? Inside a repository or outside of that repository? If possible, describe the pros and cons of both methods.
PS: Personally, I would take DataJson out of the repository, since the model and methods in one place worsen the readability of the code (intuitively)