Samsung galaxy j7 is a good budget phone which comes with lollipop 5.0.1 and you can update it to marshmallow 6.0.1.
It has got 13 mp rear camera and 5 mp front facing camera.
I have updated it to marshmallow and it got better in every aspect.
It comes with 5.5" hd display.
specification is as under.
1.6GHz processor
Chipset Qualcomm MSM8939 Snapdragon 615
Exynos 7580 Octa
Internal-16 GB, 1.5 GB RAM
Resolution-720 x 1280 pixels