1. Your biological father basically need to get one Registered Deed made and Executed at Sub-Registrars Office of your adoption soon after biological father – biological mother’s divorce with your step mother at the time of his re-marriage.
2. It should have been shown that your biological father after marriage has given on adoption to your stepmother “after seeking consent of your biological mother” you as her foster child and henceforth you will be known as adopted by stepmother with biological father’s given name and care for all practical purposes before any/all Authorities.
3. But if you are over 15 years old then same cannot be made at such belated stage unless custom and usage are shown is my view. Seems to me reading 1989 in your brief you are borderline case yet I need clarification of your exact age as of date to be more firm on this para views reference to your query.
4. As per rules of Ministry of External Affairs Circular No.VI/401/01/05/2008 dated 05.10.2009 serial No.4 (2) "In the event of remarriage after divorce, the name of step-father/step mother cannot be written in the passport of children from the previous marriage. The relationship of the child to his biological parents subsists, even after divorce by parents. It is also not possible to leave the column of father or mother blank in the passport in such cases. Therefore, such applicants must write the names of their biological parents in the application form. However, if the stepfather or stepmother is appointed by a Court as legal guardian, the name of such step-parent can be written as legal guardian".
5. Only grounds on which the passport can be refused by the RPO are contained in S. 6 of the Passports Act, 1967. S. 9 of HAMA provides that the biological mother of a child has the capacity to give the child in adoption. Consent has to be taken from biological father/mother as the case in generic is made out to be for adoption OR ‘renouncing the world’ should be shown in cases where consent during or after divorce is not possible due to no know whereabouts of other divorced biological parent is my view.
6. Passport Office is doing enquiry and it is within their right to do such enquiry and reject an Passport Application and such rejection does not come under Art. 14 and or Art. 21 COI. A passport is not only a travel document, but is also an identity document. The identity of a person is determined inter alia by his/her parentage. Therefore unless there is a legal adoption of the queriest he/she is bound to give the name of his/her natural parents and cannot choose to provide the name of the adopted parent(s) in his/her application form which is crux of objection I see as emerging.
Suggested to talk to your biological father and request him to hire services of mature junior Level Advocate found via reference to prepare Adoption Deed documents and seek biological mother's consent and Execute the Deed in Registrars Office then annex true copy of the same with Passport Form and that is how your Passport now will get issued with right set of annexure which is what your facts leads at the end to are some of my legal views for the purpose of this query.