Samsung galaxy s4 or asus zenfone 2(2 gb ram)

If you want 4G and 64bit processor go for Zenfone2. If you can live without 4G go for S4 since after sales is awesome and software is stable. Amoled display is also amazing + brand value

Zenfone 2 is a great overall package for the price.
S4 is almost 2 years old now and won't be getting any future software updates from samsung while Zenfone 2 might provide software updates for 2 years.
Also Mi4i is a great option at 13k.