Help with an unknown number

Hello guys!
A friend of mine is receiving calls from an unknown number from a stalker, she is upset that the person calls even in the morning such as 3 am per example. Does someone knows how to track a cellphone number? I’d really appreciate it.

Block That Number And File a FIR in police station

Try this! Many unknown numbers we receive, might have truecaller accounts.
Thus, go to Truecaller.
Type the phone number in the ‘phone number search’ bar.
You might (atleast) get some hints!
Hope it helps!
All the Best!! :grin: