Ill recommend you to go with the Honor 6X as it offers the best specification and overall performance.
Both the phones have their pros and cons,lets analyze :-
Honor 6X vs Moto G5S
Advantages of Honor 6X
1.Faster CPU:-Faster CPU means more smooth experience.
2.Bigger Screen:-more pleasing experience on a bigger screen.
3.Has Dual Camera:-Dual camera is useful in enhancing certain effects like blur, zoom and wide angle photos.
4.Bigger Battery:-It can generally last more time.
Advantages of Motorola Moto G5s
1.More RAM:-RAM means more applications can run at the same time.
2.Better Camera Resolution:-More resolution generally means better picture quality.
3.Has Front Camera Flash:-Having a front camera flash allows you to take selfies in low light.
4.Has Removable Battery:-You can replace the battery or use a spare battery when device's battery performance is degraded
Verdict - In my opinion,Honor 6X is better overall performance and price ,if you need better RAM Has Removable Battery than go you can go for Motorola Moto G5s
You can also compare these devices on 91mobilesHonor 6X vs Moto G5S
Honor 6x is better in my opinion. I am using this phone and it has nice cameras and lag free performance, good battery backup. However , Smarton Srt.Phone has snapdragon 652 processor which is more powerful but other things like cameras and battery are average. Smartron Srt.Phone 64GB vs Honor 6X 64GB
Surendra Kumar Sonbhadra