Guidance/Suggestions for Nov 2019 CA Final exam

I am planning to write CA final

I registered for old syllabus

I have some questions please clarify

1) Till when old syllabus we can write?
2) Whether converting from old to New beneficial?
What is the due date for conversation
...so that we can write exams in Nov 19
3) Elective paper which one should i take....new syllabus