Hello Rajan,
1.Use HTTP method POST.
2.Please use correct content-type(mime-type) header when u r performing POST/Create_Stream
Have a glance at the below for mime-type related info.
http://help.sap.com/saphelp_nwpi71/helpdata/en/46/bb1832ab4811d4968100a0c94260a5/content.htm
Regards,
Ashwin