Most of the Xiaomi phones provides best features with low cost.
Xiaomi Redmi 3S is one of the best smartphone under 10k INR. Sound quatity is pretty much decent. Style and Design are also satisfactory(stylish metal body). It has all basic range of feature needed in smartphone. Xiaomi Redmi 3S has excellent long lasting battery(4100 mAh). Good Camera, Processor and Ram. Basic and moderate level tasks can be easily carry out with 2 GB Ram.
I wonder how Xiaomi is able to give such features with 7k INR.