How long does it take to convert from ca final old course to new one? i need to fill exam form too!?

I had lots of personal problems in addition to failing (and losing motivation) to pass even 1 group. I was planning to convert to new final course for a few months. Finally I filled the form 2 days back. But now I am worried about the deadline for filling exam forms since I WISH to appear for final new course exam in Nov 2018 itself.
How long does it take to receive confirmation from ICAI about the conversion?
What if it doesn't arrive till the LAST date of exam forms for Nov 2018? Will I be forced to fill exam form for the old course then?

Thanks in advance.