Wheels from Opel Astra K on Chevrolet Tracker: compatible?

No, the centre bore is too small

Same 5x105 PCD, but the centre bore of the wheels from Opel Astra K (56.6 mm) is smaller than the hub of Chevrolet Tracker (108.1 mm): they will not fit without being re-bored by a professional.

Opel Astra Kfrom 2015Chevrolet Tracker1999–2009
PCD5x1055x139.7 / 5x105
Centre bore56.6 mm108.1 mm
ThreadEcrous - 12x1.50Ecrous - 12x1.25
Original wheels 6Jx15 ET37 ≈6Jx15 ET26
≈6.5Jx16 ET38
≈6.5Jx16 ET42

≈: width estimated from the original tyre size.

Before fitting the wheels

An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Chevrolet Tracker (Ecrous - 12x1.25), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.

And the other way round: wheels from Chevrolet Tracker on Opel Astra K?