Hello Prakashmohan

Your registration of CPC will remain valid (even under new schema of syllabus) for three years from the date you became eligible for appearing in CPT exam.

In case it has been three years since you registered and became eligible for appearing in CPT, then your registeration will get nulled, ONLY IF:

• You didn't appear for at least one of the last two examinations conducted before the end of three year registration period.

So, if you didn't appear for both June 2017 and December 2017 CPT examination and your registration period of three years has ended as well (counting from the time you became eligible for CPT exam), then you will have to re-register by paying a nominal revalidation fee of INR 500/-. Otherwise, you can appear for next CPT exam, without having to re-register.

I hope it clears your confusion.
All the best!