1. He need not have same surname as you.

2. If the paternity is clearly mentioned in all his documents then having a different surname should not work to his disadvantage in any manner.

School leaving certificate and other educational documents should reflect the son having surname as father 

2) for transfer of property on father demise son would have tough time If surname is different 

3) even for issue of passport you would face problems if surname is different 

For issue of passport , visa you would have problems if surname is different 

You can name your son as NARA but keep same surname as yours 

There is nothing legally wrong in this.

1. For all legitimate purposes, the Last Name (surname) should be common for all futuristic legal purposes (PAN, Aadhar, Passport, Educational Certificate, etc.... )

2. The above becomes necessary to avoid legal disputes /claims /statutory verification /property matters /income tax matters and other statutory requirements.

As of now keep your son's name according to your surname in old fashion, after making Identity document of your son like Aaddhhaar card, or Pan card... later on apply for name change  as per your wish, and when you there is appearing father's name in the document like application your name should be written as full name not only name.

There is no law in our country or in most part of the world which mandates either giving surname to the child or to give it similar to his father or mother. 

Therefore you can very well leave your child without any surname or use any prefix or suffix as hus surname. 

Nothing stops you from doing this. 

In many parts of India people use their father's, grandfather's, village's name etc as surname. Take inspiration for them, if you so like. 

No.

We are governed by Hindu Succession Act 1956 and Hindu Marriage Act 1955 in India for distribution of property and partition deed etc.

A slight difference in spelling appearing in the quieten of name of Son makes lots of difference while claiming property, legal documents, admission in Schools and colleges etc becomes reasons for dismissal of claims and rejections of admissions. 

Please do not play with Administrative Law of the Land.

See it is not mandatory or necessary that son should share either fathers or mothers surname , you  can change the name of son. There won't be any issue with the surname.

See in documents father's and mothers name are mentioned even if surname is different there won't be any issue.

Yes it is legally ok and correct there shall be no issue.

Dear Sir/Madam,

The constitution guarantees freedom to all and fundamental rights as well and there is no law binding that you should have specific surname and hence you may have any name of your choice.

It is not compulsory but a matter of practice. If you change it then you need the gazettee notification order always to justify it

Yes it is all ok

Use this name in birth certificate.

NARA xxxxx son of --- your name. And NARA xxxxx will use in all his documents, academics etc. 

There's no such law in the country that makes it mandatory for the son to have surname of his father or mother suffixed to his name. 

The son can continue with his own name without adding his father's surname to his name. 

There's no legal compulsion for that. 

What problems do you anticipate for a person not having surname to his name. 

In south India,  there's no practice of a person adding surname to his name. 

You have full rights to name your child as per your desire.

If you have decided to name your child after consulting all your family members   there won't be any dispute in the family. 

- Legally you can add your fathers name with your sons name as surname.

- Further, no problem will be create in future in India or abroad or even in the property related matters. 

- Further, it is not mandatory in India to have surname of father or mother with the name of child.

You can keep your son name son as NARA. . 

No that will never be an issue.

No problems can arise.

Yes it is. Law has nothing to do with giving names. A parent may give any name and the son/daughter may change it afterwards.

Yes it is.

No it's not a problem as long and father and mother name are mentioned in all his documents.

1. As per the information mentioned in the present query, makes it clear that you wish to have clarity over including the surname same or a as different from the existing surname of father or fore father.
2. I would like to apprise you that there is no illegality involve in having the different surname as surname doesn’t depict the relation of father and son.
3. The documents of identity and schooling having the name either with different or same surname, shall be the proof of relation between father and son.