It's going to be tough for me to help, because I have no experience whatsoever with that device. Here are some general things you can try:
1. Boot into Safe Mode, which temporarily disables all 3rd party apps. If the problem goes away in Safe Mode, then something you installed is causing the instability, and you may have to uninstall app one by one until you figure out which one is the culprit. On most Android devices, to get to Safe Mode, press and hold Power until you see the Power dialog box. Then press and hold the Power Off selection until you see the Safe Mode prompt. Tap OK, and the phone will reboot into Safe Mode.
2. See if you can boot into Recovery Mode and wipe the cache partition, which won't erase any personal data. I have no idea if this video will be helpful, because (a) it's for a different model iBall, (b) the display shows a Chinese language recovery menu, and (c) the overall quality of the video is poor, without any narration at all. But it's the only thing I could find. Try the button press combinations shown, and if you can read the menu, make sure you select Wipe Cache Partition, then Reboot System Now.
https://www.youtube.com/watch?v=VpBiZgFdka8
3. A last resort would be a full factory data reset, which will wipe your phone.
Good luck!