You needs to fill separate application forms for each duplicate certificate.
By applying for duplicates should keep in mind the varying fees according to the year of passing and get the demand draft prepared accordingly. The application should be sent to the Deputy Secretary, Central Board of Secondary Education, Todarmal Marg, Ajmer, (Rajasthan) along with the fee. Those who are personally applying can deposit the fees in cash in Ajmer office.
The documents will be received after 15 days excluding the holidays.
The certificates shall be collected within three months from the date of depositing the fee otherwise it will be cancelled and the candidate will have to apply afresh for procuring the documents.
One should not forget to mention the correct name, parents name and roll number while applying.
In case of emergency, the documents can be prepared within 2 days. An extra amount of fee is to be paid for getting the documents early.
Migration certificate will be issued only to the successful candidates or those who have been placed in compartment order while seeking admission for further studies. The failed candidates should not apply as they will not be granted the migration.
The revised fee for the documents can be seen through this link- http://cbse.nic.in/faq/notice%20of%20fee%20revision_2016.pdf