There's no single answer to how many miles a 1994 Chevy Tahoe can go. The lifespan of a vehicle depends heavily on maintenance, driving habits, and environmental factors. Some 1994 Tahoes might have been driven only a few thousand miles and are still in great shape, while others with poor maintenance might have experienced significant wear and tear at far lower mileages.
You'll find 1994 Tahoes with anywhere from a few thousand miles to well over 200,000 miles (and possibly even more in exceptional cases). There's no inherent mileage limit. It's about the condition of the vehicle, not the odometer reading.