Often, these specifically named files are part of a localized internet meme or a "leak" from a social media influencer.
Files shared with generic names like ".mp4" on public forums can sometimes contain malware or "screamer" content (sudden loud noises/jump scares). Always scan the file with updated antivirus software before opening.
While the specific content of a file named "nisha1.mp4" can vary depending on where you found it, it typically refers to: