For example, let us consider the part 85408. If you copy paste and enter this part number in the search bar located on the top right corner of idt.com (Auto mode), it will take you to the products landing page.
You can find the package type and package code info under the product options section in the landing page. When you click on the package code PGG24, it will lead you to link where we have the RoHS certificates.
Alternatively, if you already knew the package code, you could enter it in the search bar on the top right corner of the website, click on the package option and search. You can also go to this link.