Flashing firmware often wipes the device. Use Samsung Smart Switch or cloud storage to back up your personal data.
Open Odin as an administrator and connect your tablet via USB. A "COM" port indicator in Odin will light up when the connection is successful. Samsung SM-T210 Firmware
The Samsung Galaxy Tab 3 7.0 (SM-T210) Go to product viewer dialog for this item. Flashing firmware often wipes the device
Flashing the stock ROM can resolve software loops or "bricks". Samsung SM-T210 Firmware
Download the Odin 3 tool and install the latest Samsung USB Drivers on a Windows computer. Firmware Flashing Guide (Odin Method)
Power off the tablet. Press and hold Power + Home + Volume Down simultaneously. When a warning screen appears, press Volume Up to enter Download Mode.