Sindhu,
You can pursue whatever you want professionally. To switch your major from Engineering to Journalism, you need to convince the Office of Admissions and the Department of Journalism that you are capable of grasping the journalism related courses at a graduate level. For that you need a very good score in GRE, especially in the verbal section. Also the letters of recommendation and the Statement of Purpose play a very big role. To make your case strong, get a few articles published in reputed newspapers and magazines. Mention this in your SOP and also include the newspaper cuttings of these articles in your admission packet. If published online, mention the links in your SOP. When you get admitted to the school, you will have to take a couple of courses from Undergraduate level. This only helps you with your higher level courses.
Most important advice: When you write anything, use the correct spellings and punctuation marks. Else, no one will ever take you seriously, especially in the field of Journalism.