Company's Creditor Gets Served

Arshiya Group of Companies (a Pvt Ltd firm) issued 10000 convertible warrants to an investor, which were fully paid. Later, the company didn't file the necessary documents with MCA for conversion. The investor lent more money to the company, but the management just used it to pay off debts. Investor now wants to recover his unpaid amount. What legal remedy would the investor have against Arshiya Group?

Is it through a derivative suit under section 399 of the Companies Act or by making an application under section 241 to the NCLT to pass an order that the company must convert the warrants into equity shares?