

It’s actually a pretty rare sight. The pictures you see online are mostly historical, and sometimes Bangladeshi. (I have nothing against them. In fact, I speak Bangla as my first language and can relate to them more than I do to north and south Indians. But they do still have that issue to some degree.)
It’s very hard to find non-electric trains in India. In my >23 years spent there, the only time I encountered those were in the hill regions. And this map does align with that i.e. places with high altitude railway tracks seem to have a lower percentage of electrification in general.