Sir this is my first post in c# section:

I want to apply this format to textbox


What type of textbox should I use?
Textbox or MaskedTextbox

and how to apply format like this 999,999,999

Is there any specific property in propery window or I should use some procedure?

Please help

I think the first step would be to format your number to the string you want to use in that textbox. seems to find plenty of priors so let's skip to the textbox.

You didn't ask about a popup so in C# the textbox has properties and it's as simple as

tbSettingText.Text = "Initial text contents of the TextBox.";

So now that you have your formatted string, you seem to be ready.