I don't know whether to trust this phone in Amazon India, the specs are too good yet phone is so cheap but the reviews said that they couldn't believe it's this cheap either but it works well.here are the specs:

16MP+2MP dual rear camera with f/1.7 + f/2.4, flash/soft light back LED flash | 16MP front camera
16.002 centimeters (6.3-inch) IPS in-cell LCD FHD+ multi-touch capacitive touchscreen with 2340 x 1080 pixels resolution, 408 ppi pixel density | 2.5D Gorilla Glass 3
Memory, Storage and SIM: 8GB RAM | 128GB internal memory expandable up to 256GB | Dual SIM (nano+nano) dual-standby (4G+4G)
Android v8.1 based on ColorOS v5.2 operating system with 1.95GHz Qualcomm Snapdragon 660 AIE octa core processor, Adreno GPU 512
3500mAH lithium-ion battery
1 year manufacturer warranty for device and 6 months manufacturer warranty for in-box accessories including batteries from the date of purchase
Box also includes: Adapter, Micro USB Cable, Booklet with Warranty Card, Quick Guide, SIM Card Tool, Screen Protect Film and Case