MBA/PGDM

Thanks for the A2A. I will try to answer the question to the best of my knowledge.
The main difference between getting a MBA in communication management and doing a degree in mass communication and journalism is what you will be doing after getting these degrees.
If you take upmass communication and journalism, you are responsible for creating content. You learn how to create content, how you can look at different ways to structure content, figure out your individual style and learn to extend the boundaries of your creativity.
If you do a MBA in communication Management, you will be managing content. You form the linkage between the creative team and the product expected for your firm. This is a more management-oriented kind of job.
For example, if you are approaching an ad agency for creating your ad for your firm, you would be responsible for giving a brief of what the ad should project the attributes of your product. You specify the target audience and the style of this ad.
The ad agency takes your inputs, analyses your brief and their creative team design an ad for your campaign. You would judge their content, decide if there have to be changes and so on. You would also be responsible for targeting , revenue allocation such as what is your spending for the different modes of communication- how much are you going to spend to air this ad on TV, how much on social media, etc.
One more distinction is that the MBA grad on average would be earning more than the creative team who are the actual brains behind the ad.