How I should reverse broken text to normal text in microstation?

How is the text "broken"?
If you mean dropped into individual graphic elements, there is no way to recover that. New text will need to be placed.

Text was mistakenly broken by doing drop element.

Thanks for your quick response for my question.

One suggestion,

If you are still able to use the undo command stop where you are. Leave the file open in Microstation. Make a copy of the file in Windows Explorer. Now use the undo command in the current file to the point where the dropped text is restored. Now delete out everything but the text in the current file. Reference in the copy of the file and copy all elements except the dropped text.

If you've already closed the file or compressed it then you will need to recreate the text manually.

Unfortunately there is no such tool in Microstation.

AutoCAD has such tool to fix broken text - PDFSHXTEXT

Another possibility if you have access to Descartes is to save the file as an image and then use  Optical Character Recognition to convert back to Text.