Change in date of birth

Dear Sir / Madam,

                        I am writing this query on behalf of my wife. Her actual date of birth is different from the date which is mentioned on her certificates and documents. There is a difference of almost one year in the register maintained the corporation office.

                       Now she is planning to apply for a Birth Certificate. Please let me know what are the formalities and documents necessary for submitting the application.

                      Is there  any rules or possibility to obtain a birth certificate with the date mentioned on her school certificate and passport?

With regards.

Nobin.