Since your birthdate is 23rd September 2007, here's how many attempts you can make for the National Defence Academy (NDA) exam.

The NDA exam is conducted twice a year by the UPSC, and candidates must meet the age criteria as follows:

- The age limit is generally between 16.5 and 19.5 years.

- For most NDA exams, the candidate must not be older than 19.5 years on the commencement date of the course, which is typically in January or July of the following year after the exam.

Given this, let's calculate:

- By September 2024, you will turn 17 years old, making you eligible to appear for NDA in 2024.

- You will remain eligible for the NDA exam until you turn 19.5 years old, which will be around March 2027.

Therefore, starting from 2024 until 2026 (since the NDA is held twice a year), you can attempt the NDA exam for **5 times** (from NDA 2 in 2024 to NDA 2 in 2026). Keep an eye on specific eligibility criteria for each exam cycle to confirm your eligibility.

hope this helps you!!