Service tax return

dear sir/ madam

while filling the service tax return, a error occur .........

In payable service sheet, cell C1 ask whether assessee avail any exemption notification

Cell C2 ask if yes please furnish the notification no

cell D ask S.no of the notification no( if abatement is claimed as per notification no1/2006 st)

I filled in C1 yes

C2 13/2008-st and Cell D keep blank. than upload the filen next when i checked the status returned rejected sr no not filled any 1 guide me what should be fill in that column, Assesse are GTA receipient and avail exemption.

Please help............