6546 is divisible by:
The unit digit is 6, so 6546 is divisible by 2.
Sum of digits = 21 which is divisible by 3.
Since 6546 is divisible by 2 and 3 both, it is divisible by 6.
Here 6 + 5 + 4 + 6 = 21. 21 is not divisible by 9.
Therefore, 6546 is not divisible by 9.