You don't need to enable VoLTE. Insert the Jio (VoLTE enabled) in any slot. Just Put the SIM in the phone and make sure the phone is on 4G network. you can use the VoLTE feature.
You can check the specs here: Zenfone 4 Selfie
Google Assistant Setup
Note: You can also be asked to activate the Voice assistant where you will be asked to record "Ok Google" three times.
You can also watch this video for detailed information about Google Assistant
You can go to Settings > Display and Check if there is a cast option. If there is an option, select cast option, and select a nearby device to cast upon.
The Gionee A1 mobile features a 5.5" (13.97 cm) display with a screen resolution of Full HD (1080 x 1920 pixels) and runs on Android v7.0 (Nougat) operating system. The device is powered by Octa core, 2 GHz, Cortex A53 processor paired with 4 GB of RAM. As far as the battery is concerned it has 4010 mAh. Over that, as far as the rear camera is concerned this mobile has a 13 MP camera CMOS image sensor, Exmor-RS CMO.
The power button and volume rocker are placed on the right, while the SIM card tray is on the left. As for the bottom, this is where the microUSB port and mono speaker are. At the back, Gionee A1 houses a 13MP primary camera with dual-LED flash, as well as a circular Gionee logo.
The front consists of a 5.5-inch display and 16MP selfie-shooter, soft flash, earpiece and proximity sensor. Below the display are two capacitive navigation buttons, along with a physical Home button that also has an integrated fingerprint sensor. Despite its form factor, the device is fairly lightweight and sleek. The device manages to impress us in the design department.
The MT6300 is an Envelope Tracking Module (ETM), that complements MediaTeks CAT-6 modem. The package monitors the voltage supplied to the RF power amplifier in real-time, and uses continual, fine-grained voltage adjustments to optimize the power amplifiers efficiency. By ensuring the power amplifier is operating at peak efficiency it reduces heat generated in the phone, particularly during LTE-A and Carrier Aggregated service use. MediaTeks ETM package can save up to 20% current at max output power level.
Adaptive Picture Quality
Helio P 10, the MediaTek P series is really powerful when it comes to processing speed and battery life.
Inference: It is a good buy at this price.