deed of adoption can be executed duly stamped and registered wherein you give your child in adoption to second wife 

2) there should be giving and taking ceremony 

3) also obtain court orders n this regard 

Dear client,

The Hindu Adoption and Maintenance Act, 1956, governs the legal procedures involved in adoptions in India. Given that you brought up your first wife, and presuming you are Hindu, your second wife would need to petition the family court to be adopted. She must demonstrate her suitability and desire to adopt the child. It is important that the consent come from the parents who are still alive, but since your first wife passed away, you will also need to present legal proof of this. The requirements for a lawful adoption are outlined in Section 7 of the Hindu Adoption and Maintenance Act. For the adoption to be officially recognized, your second wife must get a court order. This entails a careful assessment of the child's welfare and her suitability.

Hope this helps you.

The stepmother can adopt her husband's child of previous marriage if the mother is deceased or the mother has agreed to relinquish her rights as mother. 

You can get the custody for your son. She doesn’t need to adopt or you have custody 

Hello - Your second wife need not to adopt your child / son legally - All rights of your son are due to you. 

Register with CARA - Child Adoption Resource Information and Guidance System. Follow the guidelines. File an application in the jurisdictional Court to get an Adoption Order. Adoptions under Hindu Law are governed by the Hindu Adoptions and Maintenance Act, 1965.

- For adopting a child in India, married couples need to have a combined age no older than 90.
- Further, married Couples should be married for more than two years
- Further, the average age of a child to adopt should be from 18 months to 8 years old
- Further, all adoptions in India are required to follow the procedure set out by the Central Adoption Resource Agency (CARA).

- Hence, your wife can file a petition before the court for adopting the said son