If you manage to find this collection online (and we will discuss legality later), here is typically what is inside:

NeoRageX was one of the first widely accessible emulators for SNK’s Neo Geo hardware. Version is particularly remembered for its polish, speed, and compatibility with a broad range of Neo Geo MVS and AES games. The 186 ROM set refers to a curated collection of 186 unique Neo Geo titles that ran well on this emulator.