How do i trigger tab key on press enter key?

Question is why do you want to trigger the tab key on Enter key press?

Is it to insert a tab in the RichTextbox?

If so, what if you want a new line which is the default action, if you want the Enter key to trigger a move to the next control in tab order then you will need to look at the RichTextbox Keydown event.

You do not provide enough information to know what exactly you want to do when we know what you are after then someone may be able to help you.