I contacted the Logitech and this is the reply:
Dear Prakash,
My name is Marissa R., I understand that you would like assistance with your G602 Wireless Gaming Mouse.
This is to inform you that it is normal that the serial number on your mouse is different on the box.
In line with warranty...
My Logitech G602 also have this problem!
Both serial numbers on the mouse and packaging box doesn't match....
Imported on OCT 2013 by RASHI PERIPHERALS PVT .LTD
Hi Guest we just wanted to alert you to a major change in the forum. We will no longer be allowing the posting of outgoing links. Please use the attachment feature to attach media to your posts.