Opinions on what the 6th pokemon for my team could be.
Team so far:
Mega scizor- bulky SD +roost
Latios- defog, hp fire
Conkeldurr- assault vest
Landorus- physically defensive SR setter
Rotom-w - specially defensive
A physical wall breaker for Scizor would be useful. Something like BD Azumarill could help. It patches up your weakness to a few sweepers (Zard X and Gyarados) as well as break down physical walls for Scizor to clean up late-game. Not to menton you have Conkeldurr to deal with Ferrothorn and Rotom-W, two of the most annoying Pokemon for BD Azu.
Try the RMT section of Smogon. http://www.smogon.com/forums/forums/xy-ou-teams.261/
You will get far more detailed help. (In theory).
As a Rater, I would ask you to please not direct people with incomplete teams to RMT, considering posting such teams is explicitly against the rules.