select case month(tarih)
          when 1 then 'Ocak'
          when 2 then 'Subat'
          when 3 then 'Mart'
          when 4 then 'Nisan'
          when 5 then 'Mayis'
          when 6 then 'Haziran'
          when 7 then 'Temmuz'
          when 8 then 'Agustos'
          when 9 then 'Eylül'
          when 10 then 'Ekim'
          when 11 then 'Kasim'
          else then 'Aralik'
       end as ay
      ,sum(case ba
              when '1' then convert(decimal(18,2),isnull(tutar,0))
              else 0
           end
          ) as borc
      ,sum(case ba
              when '2' then convert(decimal(18,2),isnull(tutar,0))
              else 0
           end
          ) as alacak
  from limon2012.dbo.tblmuhfis
 where hes_kod='120-01-002'
 group by month(tarih)
 order by month(tarih)