what is the correct coefficients of kclo3-kcl+o2?

Answer 1

With MnO₂ as a catalyst, the above equation is correct. However, in the absence of a catalyst, the initial reaction is a disproportionation, not a decomposition:

4KClO₃→3KClO₄+KCl

Answer 2

2KClO3 ===> 2KCl + 3O2