How to port any mobile number :

Step 1: Send the following text message -

PORT followed by your 10-digit mobile number to TRAI's central number for mobile number portability - 1900.

Example: Send 'PORT 91xxxxxx91' to 1900. You'll receive an SMS back with a Port out code.

Step 2: Then go to mobile store on which telecom operator you want to port.

Step 3:  Complete your KYC details by using Aadhar card.

Then enjoy the 4G world.