The 2SC5263 is covered by this 103 KB PDF, listed among schematics in the index. Following Japanese JIS numbering, 2SC marks an NPN bipolar transistor, and no variant letters are present in the name. Open it in any PDF reader to check pin layout, package dimensions and maximum voltage and current values. In practice it supports out-of-circuit testing and the selection of a replacement, after confirming that the code printed on the original component really corresponds to this number.
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.