The errors can be solved out with the help of firmware and Huawei Unlock Code generator software, and which download link is available at the end of the article.
How to solve the error of BSNL / Tata Docomo (Error 619) in Idea E1550 modem?
1. Download the unlocking software and firmware for Idea Huawei E1550 modem.
2. Run the Huawei Unlock code generator tool.
3. Generate the unlock code / flash code for your modem through Huawei tab and note down it.
4. Now run the firmware and use flash code as password when it asks.
5. Wait for finish the process and you have done.
Now you can enjoy error free Idea Huawei E1550 modem.