Hi Roel,
Finally I got response from Oracle stating that I should purchase the common voucher from NIIT (common means valid for SCJP/SCWCD/SCBCD etc.)
Below are the steps:
1) Get voucher (and voucher number) from NIIT
2) If voucher number does not start with 'SC', get it replaced by Oracle with another voucher whose ID starts with 'SC'. For this, we have to drop mail to
suncert_ww@oracle.com with subject line 'Replacement Voucher for IBT' and provide the voucher (only voucher number is sufficient). This voucher will be cancelled and we get a new voucher starting with 'SC'.
3) Go to www.pearsonvue.com/oracle
4) Click on Schedule A
Test
5) Select "Master Assignments" under "What type of exam are you planning to take?" section
6) Login with your Pearson Vue user name and Password
7) Select 1Z0-855
Java Standard Edition 6 Developer Certified Master Assignment (Step 1 of 2) from the list
8) Pay for the exam purchase (here, we have to put the voucher number. if the discount is already selected, please continue with this. if there is failure saying that discount is not applicable, go back to payment step, re-enter the same voucher number and remove discount option. it should work.)
9) Confirm the purchase by clicking the "Confirm Order" button.
10) You can click on Begin Exam to download the assignment (begin exam has nothing to do with actual beginning of the exam). Download it ASAP and make backup copy first
It would be a jar file containing an html file and a .db file.
I wish this would help and save time of other developers(especially in India) who are planning for this exam.
Currently I'm working on my assignment and will keep on asking doubts