Lg g3 D856

Hello guys..
Is it possible to install LG g3 D858HK 30A official marshmallow Rom in my LG G3 D856 using LG support tool..? If Yes then is there any backdraws..? Please help me as i cant find root methods for my LG D856 30B official marshmallow Rom but LG 858HK root ia available..

[D856] MarshMallow Root and Recovery Available?

is root and recovery available for MM d856?

How to root Lg G3 D856 Marshmallow

Hello.. Did any one know how to root Lg G3 D856 marshmallow..i recently updated my lollipop to marshmallow using Lg support tool and i want to root..i tried one click script ,kingroot kingo root from mobile and from pc also, towel root none of them working.. Any one know how to root it..?