Genuine currency notes have a floral design in the vertical band next to the watermark.
The watermark window contains a portrait of Mahatma Gandhi with the number "100". These two are key markers in identifying a genuine Rs 100 note.
Apart from these, the security thread in a genuine Rs 100 note contains the inscriptions "Bharat" and "RBI".
They change to blue and green when viewed from different angles.
The inscription "RBI, 100" is visible in the space between the vertical band and Mahatma Gandhi's portrait.