I think no, he can be a director with the permission of council but he can not be appointed as WTD.
The meaning of Whole means if he occupying the position as whole he can not take responsibility as whole in other capacity.
For example, As per section 161(1) of the Companies Act, 1956 Annual Return should be signed by a director and CS and if such cs is also WTD then how can he signed in both capacities.
Same case in signing of Balance sheet and profit and loss a\A/c.
Other, Example, if u are filing Form-32 of appointment of WTD who is also CS whose Form-32 was already filed with ROC then what option u will take like change in position .
After filing Form-32 with ROC with change in position of CS the MCA portal automatically delete the column of secretary by reason of STP method.