First of all get the SIM blocked immediately
As soon as the phone is lost, the first thing to do is call your mobile network. Whether your number is of Jio, Airtel, Vi or BSNL, tell the customer care, ‘My phone is lost, switch off the SIM immediately.’ As soon as the SIM is switched off, OTP will not come, calls and SMS will stop, the biggest route of fraud stops here. This is the most important and first step.