mumbai, Oct. 20 -- RBL Bank Ltd expects to secure regulatory approvals in the next five to six months for a $3 billion investment from Emirates NBD, a deal that would ultimately transition the Indian private bank into a listed subsidiary of the foreign bank. As part of the acquisition, RBL Bank will be merged with Emirates NBD's wholly-owned subsidiary currently operating in India. The Dubai-based lender is expected to make the first tranche of its investment in eight months from now, managing director and chief executive officer R. Subramaniakumar said on Sunday. A day earlier, the two lenders had announced what would be the biggest foreign direct investment in the Indian banking sector. At a press conference on Sunday, RBL Bank executives...