Anil Ambani group firm Reliance Energy announced its subsidiary Reliance Power will go public soon."The Board approved that Reliance Power, a subsidiary of Reliance Energy, will undertake an initial public offer of equity shares," a company spokesperson said, immediately after a Board meeting chaired by Ambani.Reliance Power would shortly approach market regulator SEBI with its draft prospectus (DRHP) for the IPO, he said.