It is NOT permissible to invest in, hold and derive benefit from realization of interest-bearing debentures, whether convertibles (CDs) or non-convertibles (NCDs). If the debenture is one that is ultimately convertible into equity shares and it is offered on a rights basis, only then can investment in it would be permissible, subject to the holder either selling it immediately on listing or any time till it is converted into equity, provided any interest payments received by the holder in the interim, are donated to charity.<
Allah knows Best...