Since marriage is being solemnised before marriage registrar under special marriage act the photographs  needed would be of actual ceremony before marriage registrar 

2) other photos would not suffice 

In your case, you can get a sworn affidavit, alongside sworn statements from your friends and family who were present at your marriage. 

if the marriage was performed according to Special Marriage Act (“Court Marriage”, “Civil
Marriage”)
- Certificate of Marriage according to Section 13 Special Marriage Act
- Photographs of marriage or function

 As per above you can attach Photographs of marriage or function

Photos before marriage registrar are suffice not as it proves marriage solemnised under special marriage act 

You don't have to mention that these photos were taken before marriage, you can just attach the photos describing that these were captured at the time of marriage function and send it across, do not invite trouble by being very honest on this. 

Yes

Checklist for a German National Visa-family reunion for spouses indicates that the Certificate of Marriage according to Section 13 Special Marriage Act and Photographs of marriage or function. So the implied meaning of function will be after the marriage. Whenever you produce such photographs, you are told that it will be taken at the time of the marriage function.

You attach the photos in your hand and describing that these were captured at the time of marriage function

- The said photographs taken at the marriage ceremony is dully valid for the said purpose with the copy of the marriage registration.

Marriage function pictures would suffice for visa purposes. They don't expect pictures in marriage registrar office.

1. They have asked "photographs for marriage of functions".

2. They have not asked photographs of the Court proceedings.

3. So, you shall have to submit exactly what has been asked.

The photographs of the social marriage shall have to be submitted.