No. NASCAR 26 is not available on itch.io. Multiple searches for a listing turned up nothing beyond unrelated fan-made or independent games that happen to share "NASCAR" in their title or tags.
Why the Answer Is No, Not Just "Unconfirmed"
This isn't a case of missing information — it's a confirmed negative. NASCAR 26 is a licensed, publisher-backed release from iRacing.com Motorsport Simulations, distributed through Steam, PlayStation Store, and Microsoft Store, per the official FAQ and storefront listings covered across this site's Platforms hub. itch.io, by contrast, is primarily a platform for independent and hobbyist developers to self-publish games, and searches for "NASCAR 26 itch.io" return only unrelated indie titles and mods tagged "nascar" — nothing connected to iRacing Studios' game.
Where to Actually Buy NASCAR 26
FAQ
No. It's not listed there. NASCAR 26 releases through Steam, PlayStation Store, and Microsoft Store only.
itch.io is mainly a platform for independent developers to self-publish. NASCAR 26 is a licensed, publisher-backed release distributed through mainstream storefronts instead.