Does this board Rk3399 support IMU sensor when using Android OS? Does anyone has developed the code to read the data from the IMU sensor?

Does this board Rockchip RK3399 support IMU sensor when using ANDROID OS?
IMU= accelerometers, gyroscope, magnetometer sensor.
Does anyone has developed the code to read the data from the IMU sensor?

IMU = Inertial Measurement Unit. Magnetometer isn’t actually part of this, although it could potentially be bundled in the same chip as IMU, however, it typically isn’t. Take as an example, the TDK MPU chips; they do NOT have a magnetometer, rather ship a second chip (AK89xx) that wires up THROUGH it.

The question of whether or not the “board” supports it is NOT the right question. Its also not the right question to restrict your scope to rk3399, but rather to compare the sensor against the 96boards specifications. The Rock960 boards (which happen to have rk3399 SoC) are more-or-less compliant with the 96boards specifications. Whether or not these boards (any of them, not just rock960) can work with a particular sensor depends on the specifications of that sensor. Essentially, the sensor needs to be compatible (or made to be compatible using things like level shifters) with the interfaces provided by the 96boards specification, which means; USB, or 1.8v UART/I2C/SPI/GPIO.

Most such sensors will use I2C+GPIO (for interrupt).
YOU need to check the voltage. If the sensor works with 1.8v, you can wire it straight in. If the sensor works with 5.0v, you can wire it in with nothing besides a level shifter. If the sensor only works with 3.3v, then you need a level shifter and a voltage regulator.

Next up is the software. Android is happy to work with ANY sensor, as long as you provide it with an interface that it understands. You can find the interface (HAL), as well as a mock implementation, here; https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/master/sensors/2.0/

There is also a wrapper for a legacy sensors library here; https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/master/sensors/1.0/

This looks to me, like a legacy driver for TDK MPU65xx: https://android.googlesource.com/platform/hardware/invensense/+/refs/heads/master – note that these sensors work on 1.8v, so they are compatible with 96boards SBCs.