Justice for Victims of Sanctuary Cities Act of 2021 This bill provides a private right of action against state and local jurisdictions with certain policies that limit cooperation with federal immigration enforcement efforts, and contains additional provisions related to such jurisdictions. Currently, such cooperation is generally not required. An individual (or certain relatives of such an individual) who is the victim of any felony for which an alien has been arrested, convicted, or sentenced to a prison term of at least one year may sue a state or local jurisdiction if the jurisdiction failed to comply with (1) certain Department of Homeland Security (DHS) requests related to arresting and detaining aliens, and (2) a DHS request to detain the alien in question or provide a notification about the release of the alien. A jurisdiction that accepts certain federal grants may not assert immunity in such a civil action. A jurisdiction (or employee of a jurisdiction) that complies with certain DHS detainer requests shall be deemed to be acting as an agent of DHS. A complying jurisdiction or employee of the jurisdiction shall not be liable in any lawsuit relating to compliance with such requests. In a lawsuit against an employee of the jurisdiction, the United States shall be substituted in as the defendant, and remedies shall be limited to provisions for bringing tort claims against the federal government.