Hi Shabana,
_init_register() is a function within CPU initialization code and is called only once. If your application is running and the it gets stuck here I would think it is resetting for some reason. You can run in stand alone mode and check the reset pin to confirm.
Then you can enable tracing to see the moment in which the MCU is reseting.
In case the reset occurs in different random moments the cuase could be hardware.
Regards,
Carlos