Hi,

The syllabus for B.Tech computer science may vary from college to college. However the difference is only slight.

you can refer the following syllabus of B.tech computer science nit trichy to have a general idea about the syllabus. The link for syllabus pdf is given below- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.nitt.edu/home/academics/curriculum/B.Tech-Ist-2013.pdf&ved=2ahUKEwir0eeGzp_sAhVQxDgGHUsUD74QFjAJegQIARAB&usg=AOvVaw1TntaxXN4iV7i8AFVL4nTU

In first year you will deal.mostly with the basics of your course. So you should focus on the class 11th and 12th subjects like physics, chemistry, mathematics and computer science. If your concept of these classess will be good it will be easy for you to study in further classes.

If you wish you can join the short term computer courses like MSC- IT, Python, c++or any short term certificate course.

Hope it helps.