Why is my Redmi phone stuck on the logo?

@hisninamrina that is usually caused by your phone not being able to "read" the firmware. Normally we do not deal with firmware/software or password issues on here. Since it is possible that your issue is hardware related, you will need to first rule out a software issue. For that, try a force restart:

• Press and hold the Power button and Volume Up button simultaneously.
• Continue holding them for 10-15 seconds or until the phone vibrates or the Mi logo appears, then release.

If that does not work you probably will have to try a factory reset. Careful with that since it will delete all of your files (music, pictures, SMS, contacts etc.) You will also need the email address/username as well as the password you've used when you first setup the phone. Without it, you wont be able to access (sort off ;-) the phone after the reset.

erase all your data.

• With the phone off, press and hold the Power and Volume Up buttons.
• Release when the Mi logo appears to enter recovery mode.
• Use the volume buttons to select "Wipe data" and the power button to confirm.
• Select "Wipe All Data" and then "Confirm".
• After the wipe is complete, select "Reboot" to restart the phone.

Let us know what you find out.