For appointment of CEO as there is no specific provisions in Companies Act, 1956 except Listing Agreement. If you want you can take appointment of CEO.No need to file any form with ROC.
But as per listing agreement, there is no mandatory clause for appointment of CFO.
You can read clause 49 as follow:
The CEO, i.e. the Managing Director or Manager appointed in terms of the Companies Act, 1956 and the CFO i.e. the whole-time Finance Director or any other person heading the finance function discharging that function.
But for Listed company it is required to have CEO/CFO for listing compliance.