Are you trying to get the max value for each IDENTITY column in your DB? that is possible by modifying the script in a previous answer to examine the is_identity column on the sys.columns table.
CREATE TABLE #x(t NVARCHAR(520), c BIGINT);
DECLARE @sql NVARCHAR(MAX);
SET @sql = N'';
SELECT @sql = @sql + N'INSERT #x SELECT '''
+ QUOTENAME(s.name) + '.' + QUOTENAME(t.name) + ''',
MAX(' + c.name + ') FROM '
+ QUOTENAME(s.name) + '.' + QUOTENAME(t.name) + ';'
FROM sys.columns C
INNER JOIN sys.tables T ON C.object_id = T.object_id
INNER JOIN sys.schemas s ON S.schema_id = T.schema_id
WHERE is_identity = 1;
EXEC sp_executesql @sql;
SELECT t, c FROM #x;
DROP TABLE #x;