Then use Borislav's code, it should work if you change it like:

DELETE FROM T1 WHERE left(rida,2) + month NOT IN;
	(SELECT left(rida,2) + month FROM t1 ;
		INNER JOIN (SELECT left(rida,2) AS Rida2,;
       		MAX(month) AS Mnt FROM  t2 ;
		       group by 1) Tbl1;
		ON left(t1.rida,2) = Tbl1.Rida2 AND;
		   t1.Month        = Tbl1.Mnt)

>This does not work.
>
>sele MAX(month) FROM t2
>
>returns global maximum only.
>I need different maximums for each left(rida,2) groups.