The rings are from 1991, 1992 and 1993, when Grant played alongside the legendary Michael Jordan and Scottie Pippen. They are size 12s and have "14k Jostens" engraved on the interior of the bands.
The rings could rake in more than $100,000 each, per TMZ Sports. Each ring will also come with a letter of provenance from Grant.
In 58 playoff games from 1991-93, Grant averaged 11.7 points, 8.4 rebounds, 2.6 assists, 1.1 steals and 1.2 blocks while shooting 55.6 percent from the floor.
Grant's Los Angeles Lakers championship ring from 2001, when he played alongside Kobe Bryant, is also up for auction and could garner more than $40,000.
The auctions close Aug. 27.