Which one should I buy under 15K?
One Plus X or Redmi Note 3
I need a better camera and display
The display quality of OnePlus X and Redmi Note 3 is quite comparable. Redmi Note 3 might even be a bit faster in the benchmarks.
But in my opinion, camera is slightly better in OnePlus X. But the difference is not major.
I suggest to you, you have already budgeted 15k for a phone. Add 8k more and get OnePlus 2. The speed and clarity of camera will amaze you. Truely fast camera. Really good quality too. Superb multitasking too. That is my opinion. For 15k, you get a 16 Gb OnePlus X. Instead, put 23k for a 64 GB OnePlus 2. Well worth it.
Else wait for Lenovo Zuk Z1 which also has Snapdragon 801 processor, 3 GB RAM, 64 Gb internal memory and 16 MP camera with
Optical Image Stabilization for 13.5k. That seems like a very good phone too. Three times the storage of OnePlux X with 1.5k less price and similar specs.