Antes de insertar los datos se puede añadir un ID con autoincrement.
CREATE TABLE `institucional` ( `n1` tinyint(4) NOT NULL, `n2` tinyint(4) NOT NULL, `n3` tinyint(4) NOT NULL, `n4` tinyint(2) unsigned zerofill NOT NULL, `n5` tinyint(2) unsigned zerofill NOT NULL, `n6` mediumint(3) unsigned zerofill NOT NULL, `nombre` varchar(128 ) NOT NULL, UNIQUE KEY `n1` (`n1`,`n2`,`n3`,`n4`,`n5`,`n6`) ) ENGINE=MyISAM;