Mass Communication

PGDM is the best option after B.Com. You are already doing your Diploma in mass communication, it will enhance your vocabulary and vocal skills which is the basic requirement for management program.
Now, you need to appear for one of the exam like: MAT, CAT, CMAT or ATMA. You should have above 50% in graduation to be eligible for good B-schools.
Good luck.

You need to a find a college offering Masters in mass communication. You can look for internships after that.

You may get into any of these colleges for pursuing Public Relation course:
1.The Xavier Institute of Communications (XIC)
2. School of Broadcasting and Communication
3. K C College of Management Studies
4. University of Mumbai
5. Department of Communication and Journalism

If you wish to make your career in media industry, you should pursue a Bachelors course in journalism and mass communication.

To become an actor, you can join acting schools after completing class 12th. You need to learn the skills, master them and then you are industry ready. But, make sure that you put your 100% efforts, as film industry makes you struggle a lot, if you don't have good contacts.

Yes, you can surely pursue PG in mass communication. This will give you the flexibility to work in various media segments.

As per UGC approved universities list for 2016, the university does not have UGC recognition. So, if you have recently taken admission, then I fear about the validity. But, if you are already a graduate, then you need to see whether the university had recognition in that year or not.

Dear Nithin,
There is no specific time to enter in the film industry, if your skills are good and have good contacts then, entering into the industry becomes easy. However, without contacts getting work is something that you struggle for. So, become the best in your field and then enter the industry.
All the best.

A journalist who writes for online portals is referred as digital journalist. So, you can pursue Bachelor degree in journalism to become a journalist, and then you can opt for working in web portals.