(b)"chargeable" means, as applied to an instrument executed or first executed after the commencement of this Act, chargeable under this Act, and as applied to any other instrument chargeable under the law in force in the territories of the [State of Karnataka] [Adapted by the Karnataka Adaptations of Laws Order, 1973 w.e.f. 1.11.1973] when such instrument was executed or, where several persons executed the instrument at different times, first executed;