@rahul
For Atpl Nav and Radio aids you are not considered passed until the day you pass the oral exam
So legally speaking it should be counted from the day you pass the orals
For Atpl Met since it does not have any orals it's counted from the day you pass the written
Word of Caution ***
The DTL section has their own methods of interpreting the rules than the average person so it would be prudent to confirm it with them regarding the validity
Their interpretation also keeps changing from time to time depending on the officer in charge
@sam737
ATPL Nav syllabus consists of Mass & Balance and Performance as well . Am sure you must have seen these books among the Oxford Atpl books
Consider buying the Keith Williams books for these two subjects as well for explanations of the answers
Please refer the ATPL syllabus thoroughly prior to attempting the exam again
http://dgca.nic.in/cars/d7b-b6.pdf