If "tmm12.rar" is a specific archive file you are working with, you will need to extract it first using software like WinRAR or 7-Zip to access the text files within. If this doesn't answer your question, please tell me: are you using? (e.g., Notepad, MATLAB, Python)
do you want to create (a file, a text box in a graphic, code)? Knowing this will help me give you the right instructions. Create and Format Text - MATLAB & Simulink - MathWorks tmm12.rar
Based on your request, it seems you are trying to create a text file or text content. Here are the most common ways to achieve this depending on your context: If "tmm12