20 Rupees

The 20 Rupee denomination has an awkward history in Indian currency — it was introduced in 1972 partly to ease pressure on the 10 Rupee note, which was being overworked in daily commerce, but the public never warmed to it, and it remained among the least-used denominations in the system for years. The sheer span of this series, running across nine governors from Jaganathan through Reddy, makes it an inadvertent ledger of the RBI's leadership over three decades.

The introduction of plate letters mid-series and the addition of text below the Asoka Column from Rangarajan's tenure onward reflect incremental anti-counterfeiting adjustments rather than any single reform event. Notes without a plate letter and carrying Jaganathan's signature are the earliest in the run and the hardest to locate in collector-grade condition.