Dear Abhi,

Stretch marks are not a problem in NDA SSB medical.

As you know it is a natural thing that happens to almost every human being. So it is small then you will not be even asked about it.

But in case, if you have gone through a severe surgery and it got you stretch mark, then you will be needed to explain it properly during the medical test and maybe during interview round  too.

To know more about this exam in detail, you can click on the link below.

https://competition.careers360.com/exams/nda

I hope this answer helps you.

All the very best!