Distributing or downloading copyrighted Nintendo NSP files is illegal in most countries. While individual downloaders are rarely sued, your ISP may flag your activity, and you are technically committing copyright infringement.
For those unfamiliar with file naming conventions, "Subnautica -NSP--eShop-.part1.rar" appears to be a compressed archive file, specifically a RAR (Roshal ARchive) file. The name suggests that it is related to the popular survival game Subnautica, which was developed by Unknown Worlds Entertainment and published by Gearbox Publishing. The game was initially released in 2018 for PC and later ported to various platforms, including the Nintendo Switch. Subnautica -NSP--eShop-.part1.rar
Since that filename looks like a specific download part for the Nintendo Switch version of Subnautica The name suggests that it is related to
Downloading or sharing pirated files like "Subnautica -NSP--eShop-.part1.rar" carries significant risks and consequences: your ISP may flag your activity