Ca final - shall i convert to new syllabus?

Yes You can 

Refer Link and registered urself if not reg. earlier

https://sdb.icai.org/stud/defaul.aspx

my suggestions not to convert in new , bcuz you still have 4 attempts in old course
personally i feel that out of 6 attempts of old course starting 3 attempt are comparatively hard & then last 3 attempt will be normal so old course students can clear
may be new course paper was easy in starting 1-2 attempt & its going to be tough from 3-4 attempt
& also in may18 & nov18 only few students are there in new course so it can be a reason for easy papers

Yes I completely agree with Abhishek ...though Nov 18 old papers were tough compared to new syllabus the same need not be the case in next attempt

Thanks for your responses.

as you said you have not attempted for last 2 years better convert into new course because of the benefits
new course is new and papers won't be that much tougher as compared to old course and pass percentage will also be good in new course and why study isca instead take elective subject from my opinion international taxation and effectively you will be studying only 3 subjects your DT will improve as you will get 4 days as 2 for elective and 2 for dt

First of see the syllabus of new course and choose elective paper wisely than take decision yourself, this not the only criteria that old syllabus paper were tough nd the new syllabus papers were easy, because u know ICAI is there.