Hiii

There is noo difference between NDA-1 and NDA-2. Its just because the exam is conducted twice, its called 1 and 2 for the respective times.

For NDA-1

Notification release in January and written exam held in April and written results release in  June. After results they call you for SSB interview in August to October and overall final merit list is published in December.

For NDA-2

Notification release in June and written exam held in September and written results release in december. After results they call  for SSB interview in January to March and overall final merit list publishs in June.

So you can choose to give any of the papers among the two to get into Indian Airforce. Both the exams have same pattern and syllabus.

Thanks!!