Data Analytics Robocall Technology Act of 2021 or the DART Act of 2021 This bill requires the Federal Communications Commission (FCC) to consider establishing a process for maintaining a list of numbers that are ineligible to be blocked by a voice service provider. These may include numbers used (1) for outgoing calls by a facility that is designated to originate or route emergency calls, (2) to originate calls from a government entity, or (3) by a school to provide school-related notifications. The FCC must submit a report containing an analysis of the effectiveness of various categories of call-blocking tools and any legislative recommendations relating to this report.