Xiaomi Redmi 4A is a best phone. I am using Xiaomi Redmi 4A and it works smoothly and has good build quality. It has better processor, better cameras , better battery backup than Zen Admire Metal and Lenovo Vibe K5 Plus. Moreover , MiUi is more clean and glitch free and has more additional features.
Lenovo Vibe K5 Plus is a better phone. It has Full HD display , more RAM, better cameras. I am using it from past few months and no issues so far. Zen Admire Metal has decent specs. You can get better phones in this price. Zen Admire Metal vs Lenovo Vibe K5 Plus