Hi ARUNSHARMA101 -
I'm Kevin B. Independent advisor and a Windows user like you. I do apologize for the inconvenience that you experiencing right now, let me help you sort things out.
Do you have the product key of your windows 10 pro? Is there any specific error message when open the activation page on your computer.
Activating windows requires internet connection for it to be activated. Please check on the link below as another Independent advisor have an answer similar to your concern.
https://answers.microsoft.com/en-us/windows/for...
You can also visit the link below if you're getting error activating your windows
https://support.microsoft.com/en-us/windows/get...
Hope this will help and have a bless day!
Thanks.
Kevin B.
Independent advisor