First of all there is no journal called "IET journal", there is however an impressive collection of IET journals (https://ietresearch.onlinelibrary.wiley.com ).
Most (if not all) the IET journal titles are indexed in Scopus. Search for IET in the list of Scopus Sources Mar. 2025 (see enclosed file).
Combined with the fact that the IET is a well established institution (https://en.wikipedia.org/wiki/Institution_of_Engineering_and_Technology ) I would say: a reliable and safe choice.