simplify 216^1/6*16^-1/2*

(3^-2)^0.?

If you meant : (216^1/6)(16^-1/2)(3^-2)^0 , then

= (6^3)^(1/6) (1/√16)(3^0)
= 6^(1/2)(1/4)(1)
= (1/4)√6