If your son has passed 12th with Commerce, then he is not eligible for admission to AIT (Army Institute of Technology), Pune, because:

AIT Eligibility Criteria:

1. The candidate’s father or mother must be serving or retired from the Indian Army.

2. The candidate must have completed 12th with Physics, Chemistry, and Mathematics (PCM).

3. The candidate must appear for the JEE Main exam.

4. Admission is based on the JEE Main score.

Since your son studied Commerce and not PCM, he is not eligible for admission to AIT