Here is a comprehensive look at using iRemove Tools for the iPad 3, updated for 2021 standards. What is iRemove Tools?
According to the release notes from the iRemove team, the tool offered two primary methods for the iPad 3: iremove tools ipad 3 upd 2021
If you are looking at iRemove Tools in 2021 (or looking back at software from that era) to unlock an iPad 3, the short answer is: It is likely a waste of time and money. Here is a comprehensive look at using iRemove