The media of the nation does not only reflect the cultural and social life of its residents but also helps in developing a positive mindset.
It would sound better like this: The nation's media reflects culture, social life, and it also helps to develop a positive mindset.
Good advice by Jennyflower81. You can also use the term "National media" that refers to nation's media.
The human mind finds entertainment in the television content, such as violence and profanity that is unnatural to itself because these appear as unexplored areas as the person has always been taught to follow peace and harmony by his parents and by the society he lives in.
.... avoid writing too long sentences. They tend to confuse the reader.
I guess this essay is for IELTS or TOEFL tasks. If it is the case, you need to present your essay in at least four paras that include the introduction, two body paras and a conclusion.