The one rupee note is the only Indian banknote issued by the Government of India rather than the Reserve Bank, which is why it carries a Finance Secretary signature instead of a Governor’s. That quirk, plus the enormous number of signature and year varieties, makes it the most collected denomination in India.Value here is driven by the signature, the year, the mint and above all the serial number. A common circulated note is worth very little; a low serial, a solid or 786 number, or an intact 100-note bundle sits in a completely different range.