Crashes are usually due to internal storage issues. Please try the following:
1. Exit the game, free up some memory on your device and restart the game.
2. Uninstall some apps you do not need in your device to free up internal storage.
3. Make sure your device is compatible with the minimum system and RAM requirement. For more information, go to FAQ->System.
4. Click the Repair Button on the right side of Login screen to repair Battleground Mobile India
5. Download and install the game again.