It is very east to move from SSC to CBSE in class 7th you just need to contact the school in which you want to take admission there may be entrance test you need to pass but some school give admission directly and it is also the best time to shift because mostly State Board does not lay emphasis on English communication which will create problems later moreover,The State Syllabus generally more easier when compared to CBSE. There is the reason because questions are almost never out of the textbook and almost every question is comes in exam which is mostly taught in class with revision.