New syllabus

Yes, please refer to the FAQ issued by the Institute as on, as per which at any point of time anyone in the old course can switch over to the new course (Please refer below).

“Q41: If I have registered for Final (existing scheme) before 30th June, 2017 will I be allowed to switch over to Final (revised scheme) at a later stage? Ans: At any point of time, you can switch over to Final (revised) Course”

Further a second part in your query is what if you have passed your 1st group under the old course, then you will only have to give the second group. It is a matter of choice if you want to give 2nd group under old course or new course. What I suggest that if you are registered for the old course and your re-registration is due before your attempt for 2nd group, re-register now before 30th of June,2017 and afterwards at any point of time if you wish to convert into new course you can do the same.
For the benefits of New course over old course please analyse yourself as it depends upon your preference towards in which subject you want specialization.