goods issued 1000 pcs under cover of ARE-1, but only 900 got exported, so where the balance 100 gone, if not exported then duty is payable, thats the simple logic of Excise department
in your ARE-1 , customs has endorsed paased 900 pcs, while the front page covers 1000 pcs, so the deficit of 100 pcs stays there, under such situations , usualy immediately at the time of loading the assesee has to split the ARE-1 in 900+100 under knowledge of their juridictinal R/O, and offer the 900 pcs ARE for export, and keep the 100 pcs ARE-1 pending ( 180 days time limit is there for export, from the date of clearance)
however the assesee failed to maintain the procedure, now if the remaining 100 pcs are lying with customs then obtain a certificate from customs that part of the specified ARE-1 (quantity 100 nos ,value .......) is lying with them, subject to get loaded with next consignment, and confirming that the goods are lying in their custody.
the assesee has to communicate this certificate to CT-1 issuing authority , VIA their Range office,
at the time of next shipment ( in oct 2016) a fresh ARE-1 would be needed for 100 pcs, giving reference of old ARE-1 and invoice, with R/O endorsement, on the basis of customs certificate submitted, ..............when the balance 100 pcs would get shipped, and ARE-1 is endorsed by customs, the old ARE-1 of 1000 pcs would get mached, which no short shipment
as the process is not followed on the date of mismatch, the juridiction of maritime commissioner will be helpful to steady and allow the case, because the assesee premises and customs port both comes under his juridication.