Can I do MBA after completing journalism and mass communication (UG)?

Yes, you can. You need to score more than 50 percent marks in graduation to get admission in a college to pursue MBA.

Yes, you can pursue MBA. In order to pursue MBA, you need to be a graduate. Stream doesn't matter.

Yes, you can take admission but as your background is mass communication, first decide why you want to do MBA and in which field you want to pursue MBA?

You can go for your MBA even after completing Masters. You can surely go for it after any UG programme.

Yes, you can go for MBA.

Yes, you can. You need to be a graduate to pursue MBA.