Hii Amlan,
First of all thank you for your quick response whenever i started any discussion.
For this discussion, you suggested me to use event 0032 for rounding off item to be offset.
As i explored i find out there is a standard function available in sap fica config under integration > invoicing i.e. Define rounding key for invoice final amount and its assignment.
Using this my objective achieved now rounding item from last month invoice offset in Current month invoice and this month round off item will be sam processed in next invoice.
Regards
Arun