The central bank has already issued new look currency notes in the denominations of Rs 10, Rs 50, Rs 100, and Rs 500, besides introducing Rs 200 and Rs 2,000 bank notes.

The new look notes are being introduced since November 2016 under Mahatma Gandhi (New) series. These are different in size and design compared to the notes issued previously.

The currency notes, except for banned Rs 500 and Rs 1,000, issued under old series continue to remain legal tender.

According to the RBI data bank, there were 4.92 billion pieces of Rs 20 note in circulation as on March 31, 2016. The number more than doubled to about 10 billion pieces by March 2018.