Step 1. Download the firmware and Huawei Modem Unlocker software from Here.
Step 2. After that close the dashboard of idea modem.
Step 3. Then Run the Huawei Modem Unlocker software and put your IMEI in Huawei tab and generate the flash code.
Step 4. Note down the flash code and now run firmware 21.157.13.00.910 which you have downloaded.
Step 5. Accept terms and conditions and proceed to the next step.
Step 6. Now it will ask you for flash code / password.
Step 7. Use the flash code which you have generated for your IMEI and proceed to the next step.
Step 8. After a few time your modem will be flashed with new firmware.
Step 9. Now put another company SIM in your modem.
Step 10. Now when you connect your modem to your computer / laptop it will ask you for password.
Don’t use the password as unlock code you have got it from above step. Because it generates the password for 35series IMEI. But, your modem is of 86 series IMEI.