National Thermal Power Corporation (NTPC) green energy, a subsidiary of NTPC, is all set to launch its initial public offering (IPO) on Tuesday and make its D-street debut. Ahead of the IPO, the grey market premium (GMP) for NTPC Green Energy shares is around Rs 1-2, indicating a 1 per cent premium over the issue price. The company has fixed a price band of Rs 102-108 per share for its IPO.