New Delhi- RBI will soon introduce Rs 20 notes.New-look currency notes in the denominations of Rs 10, Rs 50, Rs 100, and Rs 500 has been already issued by RBI , besides introducing Rs 200 and Rs 2000 notes after demonetisation.The new notes are being introduced under the Mahatma Gandhi series.Notes, except for banned Rs 500 and Rs 1000, issued under the old series continue to remain legal tender.