Hi Siva,
OK, but besides the SOAP framework I feel that there is still something wrong as, as far as I understand your code, you use
<vw1:controllerKey>100</vw1:controllerKey>
and not
<vw1:key>1000</vw1:key>
to associate the disk with the controller. But 100 is the key of the VirtualPCIController and not of the SCSI controller - this is weird to me.