I got a notification in MI community app with screenshots that stated that I will get PRO subscription in Hungama.com app and my phone is an eligible one. I followed the steps and did not get any PRO account. I followed every step and logged in using my Mi.com account which I had used to buy my MI Max (Prime).

I even got an email from hungama.com after registration:

Congratulations!

You have successfully signed in with you’re Mi credentials on Hungama.com

You now have access to Hungama’s Unlimited Entertainment Service where you can browse, preview, stream and download your favourite music tracks & videos from a massive entertainment content library from Hungama, your one-stop for Unlimited Entertainment.

Below are your login details - 

Email Id: <my email@gmail.com>

Thank you for choosing Hungama, your one-stop for Unlimited Entertainment.

Warm Regards,
Customer Support Team 
www.hungama.com 

For any further support, please feel free to Contact Us.
Or you can reach our support teams on +91 (22) - 6666 4646 or +91 92234 04646.
Monday - Saturday: 9:00AM to 9:00PM (IST)

What I got in Hungama.com is normal account which has lots of popup ads.

Is this is a scam both MI.com and Hungama.com are aware about so that Hungama.com gets more members? At least I had not heard of this app before. 

I have anyway asked Hungama.com for an update. 

Updates Thu, Apr 27, 2017 at 9:16 AM

I sent a mail to hungama.com on Thu, Apr 27 and got acknowledgement on Thu, Apr 27, 2017 at 9:16 AM.

Update May 2, 2017 12 PM

Almost 4 days, and not even a reply from Hungama.com...

Got below response from Xiomi:

I would like to inform you that Xiaomi offer to the customer one year of free hungama subscription. In order to avail the offer please follow the below link and steps.

http://c.mi.com/thread-10505-1-1.html

How to avail The offer:

•Just download the Hungama app from Playstore from your Mi 5, Mi Max and Redmi Note 3.

•After the app is installed and you open the app you got Mi Account Sign In window.

•Just Sign In with your Mi acount and avail your Musical offer.

I hope the above information is helpful.

Update May 2, 2017 2.30 PM

After reminder 5, I got a mail from hungama.com providing the terms and conditions, which included MI Max and purchased after July 1st. I have replied back with a screenshot of my phone's about page which clearly says my phone is MI Max. 

After reminder 6 and tweting in twitter, I got a faster reply, but to say that they are investigating:

...

We are investigating your concern and will try to resolve it as soon as possible.

...

At least got a reply this time. Will wait for their resolution.