Divorce

As per the situation that you've explained above, it's clear that your friends husband has abandon her without any information regarding this fact. Abandonment is a legitimate ground for divorce provided under the Hindu Marriage Act (HMA) 1955.

Thus, she could file for a divorce case on the grounds of desertion. But the twist in the situation is that - "There is no communication with her husband since 2011".

However, if you cannot find your spouse, you can request permission from the court to publish a notice of the divorce in the newspaper or post a notice in the courthouse.
This is called a Motion to Serve by Publication or Posting.
In such a matter the judge can allow publication or posting if the judge decides that you have made sufficient efforts to find your spouse and your spouse cannot be found.
You must first try to find your spouse. In your motion, you will need to tell the judge in writing exactly what you did and the responses you received.

This means that you need to keep a list of the places you contact and what you do or don't find out. Save copies of any documents you send or receive. Also save any mail that is returned to you as undeliverable.

The law does not say exactly what you have to do. It depends on the situation. The judge will decide whether you have done enough.

Here are some suggestions about what kinds of efforts the court wants you to make to find your spouse:
1.) State the last time you saw your spouse and where.

2.) Send the court papers by certified mail, return receipt, to your spouse’s last known address. Also send the papers by regular mail. Save the mail when it is returned to you and attach copies of the envelops, which will show that the mail was returned to you as undeliverable.

3.) Check your spouse’s last known address in person, if possible and if you have no concerns about doing so.

4.) Contact your spouse's last known job, if any.

5.) Check with any of your spouse's family members that you can contact.

Once, you've completed all these, you're qualified enough to prove the abandonment of your husband, and thus the court will allow you in to remarry on such basis.

Hope it Helps

Thanks