Hii there,

If you are not satisfied with your marks and you think that if you get another chance  you can score a high percentage and you are ready to work hard for it then it's a good decision to give improvement exam. Regarding change in syllabus and patterns,  I will say that there's only a slight and nominal change in the syllabus and pattern.

The students who have passed the exam in 2019, as well as 2018, are eligible to appear for the improvement exam in 2019 (consecutive year). Details of students who appeared in 2019 will be auto-generated. However, students who appeared in 2018 or earlier, will need to submit the details on the online form. In the improvement exams, the student can choose 1 or more subjects to appear. But he or she cannot appear in additional subjects (subjects not enrolled for in the previous year).

I hope your doubt is cleared. Good luck!