From IMS:

I have not heard officially about the test being open to the public yet, but I don’t see why it wouldn’t be.

The 2025 Indianapolis 500 presented by Gainbridge Rookie Orientation Program (ROP) will take place in the morning of Thursday, Oct. 10, followed by a four-car NTT INDYCAR SERIES test in the afternoon at Indianapolis Motor Speedway. The NTT INDYCAR SERIES will host a group test consisting of one car from 11 race teams Friday, Oct. 11. Nolan Siegel will attempt to complete ROP on Thursday. The test involves a series of laps at three controlled speed phases on the 2.5-mile oval. The Rookie Orientation Program is a prerequisite for participation in the 109th Indianapolis 500 presented by Gainbridge on Sunday, May 25, 2025. THURSDAY, OCT. 10 (Indy 500 Rookie Orientation Program, NTT INDYCAR SERIES Test) Nolan Siegel, Arrow McLaren Marcus Ericsson, Andretti Global Pato O’Ward, Arrow McLaren Alex Palou, Chip Ganassi Racing Josef Newgarden, Team Penske :9 a.m.-noon: Siegel ROP 1-5 p.m.: Ericsson, Newgarden, O’Ward, Palou NTT INDYCAR SERIES Test FRIDAY, OCT. 11 (NTT INDYCAR SERIES Group Test) Santino Ferrucci, AJ Foyt Racing Marcus Ericsson, Andretti Global Christian Lundgaard, Arrow McLaren Alex Palou, Chip Ganassi Racing TBD, Dale Coyne Racing Ryan Hunter-Reay, Dreyer & Reinbold Racing Alexander Rossi, Ed Carpenter Racing Conor Daly, Juncos Hollinger Racing Helio Castroneves, Meyer Shank Racing Graham Rahal, Rahal Letterman Lanigan Racing Josef Newgarden, Team Penske 10 a.m.-noon: NTT INDYCAR SERIES Group Test 1-5 p.m.: NTT INDYCAR SERIES Group Test