Compare Lenovo K3 Note vs Xiaomi Mi 4i vs YU Yureka vs Redmi Note 4G

A comparison between the devices you mentioned on the basis of some key aspects would be as follows -

Design and Display
All of the devices are blessed with 5.5 inch screen except Mi4i being the smallest of them at a 5 inch screen. Lenovo K3 offers full HD display. Mi4i is the best with full HD IPS display. Yureka and RedMi Note provide 720p HD display. In terms of quality of display Mi4i is the clear winner.

Hardware
Yureka and Xiaomi Mi4i are powered by Snapdragon 615 Octacore processor with a clock speed of 1.5 GHz. RedMi Note lags behind with Snapdragon 400 quadcore processor at 1.6 GHz. All of them should have no issues with the performance. However Lenovo K3 packs in a robust 1.7 GHz MediaTek Octacore processor. K3 has maximum power. In terms of internal memory RedMi Note is the least of them with just 8 GB memory. All other devices puffer 16 GB internal memory. However, RedMi Note has expandable memory of 64 GB while Yureka and Lenovo K3 support upto 32 GB. Mi4i is the least desired as it has no option for memory expansion. All of them have the similar 2 GB RAM.

Camera
All of the four devices have similar rear camera of 13 MP. All should be decent performers in terms of camera functionality. Camera on mi4iMi4 is the best among them followed by RedMi Note, Lenovo K3 and Yureka. Front snapper on all of them is of 5 MP.

Battery and other features
RedMi Note has the maximum battery capacity of 3100 mAh. Mi4i and Lenovo K3 carry a 3000 mAh capacity while Yureka lags behind with 2500 mAh. Lenovo K3 claims a standby time of 750 hours and talk time of 36, hours which is the greatest by any standard if true.
Connectivity features on the devices match almost similar. All the three devices except RedMi Note run on Android Lollipop. RedMi Note is struck on outdated Android Kitkat.

My Take
Lenovo K3 great on paper. Since the device is yet to be available to the user's, it may be too early to evaluate it. But given the spec sheet, it excels in processor capacity and a better combination of specifications. Lenovo K3 costs around Rs.10000 while Yureka and RedMi Note cost Rs. 9000. Mi4i costs Rs. 12999 which lacks many of the good points in the other three phones is quite out of contention. I would think Lenovo K3 would be a better bet.