See an affidavit of same name can be prepared stating Hari om and Hariom is if same person and he shall be know as Hari Om from this day onward . After affidavit there can be newspaper publication of same.

This i n problem at all.

His name is very much remaining unchanged and keeping Hari Om or Hariom makes no change in it or giving any confusion over this.

Merely because there is some space between first and last name it would not create any problems in future 

the name remains as Hari Om only there is some spacing between the words 

You can use HARI OM or Hariom 

There is absolutely no problem with regard to the space between first name and last name.

Leave it as it is. If any query is raised with regard to the same, he can given an Affidavit, confirming the same.

You can use Aadhar & 12th Certificate. 

No problem. This is not a discrepancy in name spelling.

Use name without gap.

You can use Hariom which is in government identity cards and 12 mark sheet.

The one which is found in most of the public documents.

Both are legally two different names and not one and the same, hence to make it as one and the same, your brother may get a notarised affidavit  and get it published in a local newspaper or adopt the change of name procedure

You ask him to first prepare an affidavit declaring that both the names are one and the same and after that he may use either of the name in future.

It requires the procedures to be adopted for change of name.

You can get an affidavit on a stamp paper mentioning that both the names i.e. Hari om and hariom belong to the same person. This will resolve your issue. 

You can use hari om or hariom.

1. It will not be a problem for your brother as only difference in name is a space. 

2. Your brother can apply for change of name in Adhaar Card and voter card on basis of 10th certificate.

3. And for certificate of 12th he can make a name declaration affidavit where all is documents are to be submitted along with 12th certificate.

He should use the name which appears on his documents of identity such as Voted Card and Adhaar Card.Matriculation Certificate has limited significance once the person attains majority.

Dear Sir,

This should not be a matter of extreme consideration.

However you can support your views on the same issue by furnishing an affidavit to this effect and stating therein what your actual name is written as.

You will have to see as to how your name is spelt in your birth certificate because that will be taken into account.

Anyway an affidavit should do your job.

You can get it rectified through Gazette notification and newspaper publication