No, as you say, media is already plural, so you can’t say “medias”. You can say “many (different) media” or “many (different) types of media” for instance.

Hello, The word media in itself is the plural form of medium, and the meaning already implies different forms of media. So we wouldn't say 'many medias', but rather 'many media'. Example sentence: Many media reported on the accident on the i90, but only CNN knew the names of the people involved. I hope this answers your question. Aleks

Just a quick note to agree with Mikkel and Aleks, and add a detail about how we use these words. As you read, "media" is plural, and "medium" is singular. When we talk about news sources, we rarely will refer to a single news source as a "medium." We think of news sources collectively (as a group), so usually we refer to "media" or "the media." "Medium" has many meanings, but the one most closely connected to "media" is (loosely translated) "substance of transmission/movement," or "environment, condition." It is most often used in technical contexts, so it is not used in everyday, informal communication. For example: "Water is the medium through which fish swim." "Viruses can pass through the medium of the cell membrane (cell wall)." "We see through the medium of our eyes."

I don't know precisely, but I have WordHunt dictionary, so there are plural form in it, on the bottom. For example if I type Cat, it will be cats, but for media there is nothing. So media has only singular form.