Hello Vinoth,
I guess you already know it, but you can get all the iTextSharp resources from their own web site which points to
sourceforge[
^]. Here you will have access to their Subversion project and this should allow you to mount the old version you require.
Of course if the newest one would fit you then no extra job would be required as you would only have to download it as usual.
As a side note, having the source code would allow you to know what is different and what could be needed to adapt your code...
Apart from that, if someone here has the old library, I guess that it won't be a big issue to send it to you... that CPian can contact you in several ways, answering this post,...
Good luck!