Is it safe to read 5V from 13th pin (PWM01) of xavier?

I am using this pin as GPIO input to read sensor state which is in 5V ttl.

No, it is not safe, PWM01 is CMOS 1.8V pin and routed out to 3.3V output thru a level shift.

That means it can level down too. So 3.3V is safe to read.