CREATE OR REPLACE PACKAGE schema1.package1 is
TYPE UserType IS RECORD
(....)
function check(Pin varchar2) return UserType ;
END package1 ;

 using (OracleConnection connection =new OracleConnection(db.Connection.ConnectionString))
            {
                connection.Open();
                using( OracleCommand command = new OracleCommand( "begin :rv=schema1.package1.check(:Pin); end;", connection ) )
                {
                    command.CommandType = CommandType.Text;
                    OracleParameter inputParam = new OracleParameter( "Pin", OracleDbType.Varchar2 );
                    inputParam.Value = "Moskow";
                    command.Parameters.Add( inputParam );
                    OracleParameter param = new OracleParameter( "rv", OracleDbType.Object, ParameterDirection.Output );
                    param.UdtTypeName = "schema1.package1.UserType";
                    param.Value = result;
                    command.Parameters.Add(param);
                    command.ExecuteNonQuery();
                }
            }