Urgent

Since you have not registered under Old Syllabus you are abviously going to register under new scheme hence you have to register for CA final first as there is a deadline for registration and after after registering yourself in ca final new scheme you can complete the above said courses in order to be eligible for appearing in May 2018 exams.  

Then you have to complete the same before appearing in may 2019 as ICAI has clearly mentioned that under new scheme a student has to complete Ad ITT and AMCS during the last 2 years of their articleship but before appearing in Final Exam