You don't have to give any royalty to them. Only if they seek any maintenance for their living you need to take care of it

In which name you have been bought up by adoptive parents name or biology parents name. If you have all your documents in the adoptive parents name then you not face any issue from your biological parents as of now you're above 28 years. 

You don’t have to give your biological parents any royalty 

2) if there was no giving and taking ceremony performed no deed of adoption executed you have share in biological parents property in case they die intestate 

Dear Siva

As there is no Legal Documentation/registered Adoption Deed executed then there is no adoption.

you should use your adoptive parent's name as I think all your documents are in their name too.

Dear sir, 

Upon adoption, the adopted child breaks all his ties with his natural parents except the right over property which was vested in him, and is considered as a natural child of the adopted parents. 

There is no concept of giving royalty under Indian Law (whether it is adopted or natural child).

There won't be any legal issues, you may get married.

Best wishes. 

Once you have been given in adoption, your ties with your biological family gets severed for all purposes and intents. They have no right on you and vice versa.

- Since, you was adopted without executing any legal documents , then legally you the son of the biological father .

- However, you are not under any obligation to give any royalty to him , except they can ask for maintenance , if they not having sufficient income for their support. 

- Further, you have right to claim over the property as well. 

There is no such thing called royalty in the human relationship.

The royalty aspect is applicable for business transactions or material things.

A royalty is a legally-binding payment made to an individual, for the ongoing use of his or her originally-created assets, including copyrighted works, franchises, and natural resources.

Some common examples of royalties include

Book royalties: publishers pay authors for the right to sell and distribute their books. Mineral royalties: companies pay landholders for the right to take minerals from their property.

If there is no proof to prove the legal adoption then you would remain the child of the biological parents only and you may not be able to legally claim any rights over your biological parents. 

If you do not want to claim any rights either from your biological parents or from your adoptive parents, then you can proceed silently with the proposed marriage to the person of your choice and live peacefully without bringing any such issues in your married life for any reason. 

1. Under Hindu Law an adoption is complete transplantation of adopted child in the family of his adoptive parents, with a simultaneous severance of all legal relationship between the adopted child and his biological parents. Adopted child is for all legal and practical reasons the biological child of his adoptive parents, hence he succeeds to the properties of his adoptive parents in the same manner as if he was their biological child.

2. However, adoption has to take place only through an adoption deed.

3. You continue to be the son of your biological parents for all legal and practical reasons as your adoption was not evidenced by an adoption deed.

4. You are bound to pay maintain your parents if they are not self sufficient. The concept pf paying "royalty'' to parents is alien to Indian law.

if you were legally given and taken in adoption then you have all the rights with the adoptive parents and you have no right or duty towards your biological parents.