From the nature of your question, it seems you are interested in learning about top tier US schools, and what would be a minimum ATAR to gain entry. Maximum would obviously be 99.95.

The first thing you should know, is that at the top US colleges, you cannot undertake law at the undergraduate level. The structure of the US education system is such that undergraduates typically enter a ‘College’ and study a Liberal Arts Curriculum before going onto Graduate School (if you wish). The university as a whole contains this aforementioned College, as well as graduate schools such as Law School, Business School & Medical School. In this light, your ATAR is irrelevant as admissions officers will analyse your undergraduate Grade Point Average instead.

However, on a more general level, to gain admission to top tier Colleges such as in the Ivy League (Harvard, Yale, Princeton) or equivalent (Stanford, MIT), students should be looking at having an ATAR above 99 as a minimum. As you move down the ranks, the ATAR requirement obviously lowers, where other Ivy League schools such as Brown, Dartmouth and Cornell will consider you with 98+ and so on.

If you are hoping to get stuck into a Law degree right away, like you can do in Australia, the United Kingdom has a similar education system in that students are not forced to study a Liberal Arts Curriculum and can choose a specific course right away such as a Bachelor of Laws, Commerce, Economics, Engineering etc. For Oxford & Cambridge Undergraduate Law, the minimum ATAR to be considered is 98.5. Other top UK schools such as LSE and UCL, you can be looking at 97+ as a minimum.