The Walkman Chanakya fonts (such as the 901 and 905 releases) belong to the DTP era in which newspapers and publishers laid out pages in software that predates Unicode. As with every font in this family of encodings, the file stores English letters and the font draws Devanagari.
Chanakya has its own key assignments. Text typed in Chanakya is not interchangeable with Kruti Dev or DevLys: switching the font on a Chanakya file produces wrong letters, not corrected ones. The reliable route between any two legacy fonts is through Unicode.
A few glyph mappings were corrected after an entry-by-entry check against IIT Delhi’s InDesignFontConverters and KrutiExtract, two open-source converters. That check covered selected glyphs only, not the whole IIT table.