how to use upper keywords

Hello Mrityunjay,

Welcome to Microsoft Q&A.

After reading all the content you have posted, may I assume that the Keyboard you are using is not like the following:

Rather, it is similar to these types of keyboard that have other characters:

These types of keyboard are generally sold in countries or regions where English is not the main language. If the default language used by the system is the corresponding language, then when using the corresponding input method, the keyboard layout will look like what you see. When you add English and switch the input method to English, the QWERTY layout is used.

The above is just my speculation. Because your description of the problem is too simple, I might not have correctly understood the issue you were trying to convey. Perhaps you are asking how to enable the function keys on F1-F12? Then why not take a look at the information in this support link:

Special keys and function keys for Surface Keyboards or Type Covers - Microsoft Support

You can quickly switch the functions of the corresponding keys by using the Fn key.

If none of these are what you want, could you share a screenshot of the keyboard here and tell me what you hope to achieve? If it's just a simple input of capital letters, in fact, pressing the Caps Lock key will do. But I think your question obviously won't be that simple, right?

Best Regards,

Kai Ho | Microsoft Q&A Support Specialist