The emulator itself is legal as it contains no copyrighted ROMs. However, it does include a modified Neo-Geo BIOS in some repacks, which is technically copyrighted by SNK Corporation.
Once you have the ZIP file, follow these steps: neoragex 5.2a emulator download
Ultimate Guide to NeoRAGEx 5.2a: The Classic Neo Geo Emulator The emulator itself is legal as it contains