You could use an equidistant font, examples here.
Now use "empty" strings(filled with say 20 spaces) and use the CoptyTo method from the string clas, to position the info from the DataGridView in this space filled string.
Append these strings now to the RichTextBox.
but uhm how can i get the strings from the datagridview to richtextbox :
example i have x numbers of row for datagridview with 4 number of columns. how can i put the datas line per line until i have exhausted all of my datagridview rows