Man, what a cool question. Indian ghost stories aren't one big monolith at all. Take the stories from Kerala, which my friend from there talks about, and the ones I've read from Rajasthan—they're completely different beasts. The 'Yakshi' in the south is this eerie, beautiful tree spirit who seduces and kills, tied to specific groves and old family curses. But up north in Rajasthan, you get the 'Churail', often the vengeful ghost of a woman who died in childbirth, lurking at crossroads with her feet backwards.
It's not just the entities, but how the haunting works. Bengali ghost lore, like in the stories of Bibhutibhushan Bandyopadhyay or even Satyajit Ray's adaptations, often has spirits deeply connected to the land, rivers, and household spaces—less about jump scares, more about a pervasive melancholy and unresolved duty. The regional soil, climate, and local history literally shape the ghost. A desert spirit feels thin, thirsty, and desperate, while a delta ghost feels damp, heavy, and patient. That texture is everything.
Folklore like the 'Mohan' in some Himalayan tales or the 'Brahmarakshas' from other regions gets repurposed in modern novels and web series, but you can always trace the regional roots if you know what to look for. The scariest part for me is often how the haunting exposes a very local social injustice.