Mac users interested in Best web browser for mac 10.6.8 generally download: Firefox 80.0 Free Firefox is one of the most popular web browsers on the market, providing numerous helpful features and quick speed to millions of users worldwide. Adobe® Flash® Player is a lightweight browser plug-in and rich Internet application runtime that delivers consistent and engaging user experiences, stunning audio/video playback, and exciting gameplay. Installed on more than 1.3 billion systems, Flash Player is.
You can't.
MS stopped support in 2005 for Internet Explorer.
If you were running a virtual machine with Windows could you download Explorer for your Mac.
If you are looking for browsers for the Mac besides Safari, consider Firefox, Brave, Opera, or Sea Monkey.
I just searched and saw this article, it might be of help
Internet Explorer Mac 2019
If you are trying to reach a particular website that calls for IE, go into Preferences in Safari, go to Develop menu, select User Agent and select Internet Explorer 11. See if the website that you are trying to reach handles that.