Dear Thanuja,
 
It is possible to retrieve a list of all users containing their name, roles and groups.
With the fallowing code example, this can be achieved:
 
var org = conn.Organizations[0];
 
var users = org.GetUsersFromUsersRelation();
foreach(var curentUser in users.User)
{
    Console.WriteLine(curentUser.Name);
    Groups groups = curentUser.GetGroupsFromGroupsRelation();
    foreach(var currentGroup in groups.Item)
    {
        Console.WriteLine("The name of the group: " + currentGroup.Name);
    }
    Roles roles = curentUser.GetRolesFromRolesRelation();
    foreach(var currentRole in roles.Item)
    {
      Console.WriteLine("The name of the role:" + currentRole.Name);
    }
    Console.WriteLine("");
}
Please note that we are getting the UsersRelation over the organization.
 
For further questions, please don't hesitate to ask.
Best regards
Alex