It is your call whether you want child to have surname of both parents 

2)generally practice is to give child father surname .

3) it should not cause complications 

Naming of the child will be done by the parents as per their desire.

There's no mandatory law that the child has to be have the surname suffixed to its own name.

Also there's no restriction in law for the child to have the surnames of both the parents.

The parents have rights to name their children as per their own choice or will and wish.

There is no law of the land which mandates taking surname of father only or taking surname at all of any of the parents.

In other word the child can use both surnames or none f it. 

In India, there is no legal restriction preventing a child from adopting any last name, and it is not mandatory for an individual to have a surname, whether derived from the father or mother. Parents are free to choose and innovate in selecting a surname for their child, and this choice will not lead to any complications regarding the child's name in the future.

He needs to do gazette notification for that no complications if same name in all documents 

There should be not any problem if you belongs in General Caste system, otherwise for applying other caste benefits, government policy, educational admission and government employment at that time it will be problematic to apply for caste certificate. 

Dear client,

In India, the custom of patrilineal naming dictates that a child takes on the surname of his father as the family name. That being said, there isn't a legal restriction on a child assuming their parents' last names. Personal preferences and cultural conventions frequently have an impact on the naming process. Legally, the lack of a uniform rule allowing for two surnames could cause issues with documentation. A single surname is typically required for a variety of official papers, including government documents, passports, and school certificates. Inconsistencies in identification and administrative difficulties may result from this. The Registration of Births and Deaths Act, 1969 is the legal framework for the registration of names. This Act's Section 15 outlines the process for entering names. Although it does not specifically address multiple surnames, it gives the Registrar the power to make adjustments.

Hope this helps you.

- As per the Supreme Court , the mother has an equal position as the father to decide surname of child under Section 6 of the Hindu Minority and Adoption Act, 1956.

- Further, there is no law which disallow to have the surnames of both the parents. 

- Hence, there will be no future complications with the both surnames.