Enable tachometer in Jetson Xavier NX

Hi, I am working with Jetson Xavier AGX and L4T 32.4.3 I wanted to read and change fan speed. How to enable tachometer?
enable tach :

I have tried this command

echo 1 > /sys/devices/pwm-fan/tach_enable

and getting this error bash: echo: write error: Operation not permitted

these are working fine for read/write rpm:
set speed :
echo 255 > /sys/devices/pwm-fan/target_pwm

read tach :
cat /sys/devices/pwm-fan/rpm_measured

Same commands worked for Nano but have issue in NX, is there any other command or way to enable tachometer in NX?

hello venkatraman.bhat,

please refer to below,