5 Rupees

Pick 80 spans over three decades, during which the note underwent several quiet modifications — signature varieties across successive governors are the primary collecting variable, with at least a dozen distinct signature combinations documented across the series. Some collectors pursue the full run by RBI governor tenure; others focus on the prefix letter blocks, which can help narrow the print period considerably.

The watermark is the sole security feature across the entire run — a notable underinvestment in anti-counterfeiting for a denomination that circulated heavily through rural India well into the 1990s.