Which Indian currency note has security thread?

Rs.1000 notes introduced in October 2000 contain a readable, windowed security thread alternately visible on the obverse with the inscriptions ‘Bharat’ (in Hindi), ‘1000’ and ‘RBI’, but totally embedded on the reverse. The Rs.500 and Rs.100 notes have a security thread with similar visible features and inscription ‘Bharat’ (in Hindi), and ‘RBI’. When held against the light, the security thread on Rs.1000, Rs.500 and Rs.100 can be seen as one continuous line. The Rs.5, Rs.10, Rs.20 and Rs.50 notes contain a readable, fully embedded windowed security thread with the inscription ‘Bharat’ (in Hindi), and ‘RBI’. The security thread appears to the left of the Mahatma’s portrait. Notes issued prior to the introduction of the Mahatma Gandhi Series have a plain, nonreadable fully embedded security thread.