I guess something like this: -

DECLARE @SQL NVARCHAR(MAX);

SELECT @SQL='SELECT '+CHAR(13)+CHAR(10)+

STUFF((SELECT ','+CHAR(13)+CHAR(10)+'NULLIF(MAX(CASE WHEN [name] = '+CHAR(39)+[name]+CHAR(39)+

' THEN [length] ELSE '+CHAR(39)+CHAR(39)+' END),'+CHAR(39)+CHAR(39)+

') AS '+QUOTENAME([name])

FROM (SELECT DISTINCT [name]

FROM test

)a([name])

ORDER BY LEN([name]),[name]

FOR XML PATH(''), TYPE).value('.','VARCHAR(MAX)'),1,3,'')+CHAR(13)+CHAR(10)+'FROM [dbo].[test]'+

CHAR(13)+CHAR(10)+'GROUP BY [length];';

EXECUTE sp_executesql @SQL;

Which returns: -

balk1 stof1 stof2 stof3 stof4 stof5 stof6 stof7 stof8 stof9 stof10 stof11 stof12

----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------

6 6 6 6 6 6 6 6 6 6 6 6 6

7 NULL NULL NULL NULL 7 NULL NULL NULL 7 NULL NULL NULL

9 NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL NULL