It looks that there is some reserved words in your query. I suggest you replace table.field by [table].[field]
try this
SELECT
[NOVI].[GBR] as gbrnov,
[NOVI].[AB] as abnov,
[NALOG1].[DATA] as datanov,
Min([NALOG1].[POCKM]) AS MinOfPOCKM,
Max([NALOG1].[KRAJKM]) AS MaxOfKRAJKM,
Max([NALOG1].[KRAJKM])-Min([NALOG1].[POCKM]) AS RAZLIKA,
([MAGACIN].[KOL])/100 AS Potr100km,
[MAGACIN].[SIFRA],
case when [MAGACIN].[SIFRA]='0991000' then [MAGACIN].[KOL] else null end as 'Gorivo',
case when [MAGACIN].[SIFRA]='0993050' then [MAGACIN].[KOL] else null end as 'Maslo',
[NOVI].[DATAP] AS poslprov,
[NOVI].[DATAS] AS poslservis
FROM
(NALOG1 INNER JOIN MAGACIN
ON [NALOG1].[GBRV] =[MAGACIN].[GBR])
INNER JOIN [NOVI] ON [NALOG1].[GBRV] = [NOVI].[GBR] where
( ( ( ([NOVI].[GBR])>=? And ([NOVI].[GBR])<=? ) )
AND ( ([NOVI].[AB])=? or ([NOVI].[AB])=?)
AND ( (([NALOG1].[DATA])>=?)
and (([NALOG1].[DATA])<=?) ) )
GROUP BY [NOVI].[GBR], [NOVI].[AB], [NALOG1].[DATA], [NOVI].[DATAP], [NOVI].[DATAS]