Conversion of optionally convertible debt instruments requires explicit holder consent; opt-out and redemption rights apply when price is undetermined. Conversion of optionally convertible debt instruments requires affirmative consent from holders; non-receipt of a notice is not consent. If the convertible portion of listed instruments exceeds ten crore rupees and the conversion price was not fixed at issuance, holders must be given the option not to convert, except where an upper price limit and its justification were disclosed at issuance. If holders decline conversion after a shareholders' meeting fixes the conversion price, the issuer must redeem the non-converted part within one month at not less than face value.