Anyone can become a DevOps Engineer. If you are really interested, you can achieve your career transition from Test Engineer to DevOps Engineer. You need a thorough understanding of all the tools and methods involved. One of the best ways to list out skills and tools that organizations value in the domain of DevOps could be scraped from job portals. Many companies post job vacancies in DevOps and demand certain skill sets.
If you are interested in making this career transition possible, check out this Cloud and DevOps Masters Course from Intellipaat. Also, have a look at the YouTube video on learner feedback of this course to get a better understanding.