Is it possible to branch change in the University Department colleges of Anna University after the first semester or year?

No way. Anna University does not permit you to switch branches for any reason. You must leave college and re-enroll in the course that you wish to pursue.

To begin, keep in mind that CS is not a core subject, but rather a study of technology. As a term, technology refers to a technique or methodology developed based on scientific principles for the application of such scientific principles in real life. As a result, CS technology is only used in other core streams such as mechanical, automobile, and civil engineering. Many innovations in the mechanical engineering field are equipped with CS technologies, demonstrating that such innovations are created by mechanical engineers and facilitated by CS engineers.

If you are truly interested in computer science, you will learn a variety of programming languages and apply them in mechanical engineering fields such as engine automation, computer-integrated manufacturing, and so on.