Listed as a schematic, this 118 KB PDF is named only 2SC4863 and is most likely a component datasheet. Japanese JIS/JEITA designation uses the 2SC prefix for NPN bipolar transistors. Inside, look for maximum ratings, electrical characteristics and the package drawing showing base, collector and emitter. The sheet helps when testing a suspect part, interpreting its marking code, or sourcing an equivalent. Confirm package and footprint match the board before fitting any replacement from another series.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.