No Ma'am.
Under the Companies (Acceptance of Deposit) Rules, 1975 “any amount raised by issue of debentures (including convertible debentures) secured by the mortgage of any immovable property of the company and that the market value of the immovable property secured is higher than the amount of debentures issued” is not considered to be a DEPOSIT.
Under Section 3(1)(d) of the Act, a Private Company is prohibited from accepting Deposit from persons other than its Directors, Members and their relatives.
Hence, the Private Company must issue Debentures only as a Secured Debenture.
A public company can issue unsecured debentures as there is no prohibition as such.
Attaching a note written by eminent writer Mr. Eshwar.
Vivek