Follow the suggestion provided by sandeep.
Further more if you have kept control's inside TemplateField then you will not be able to fetch the value directly.
Suppose there's a Lable inside TemplateField Then use following.
Label lbl = (Label)gridview.Rows[1].Cells[2].Controls[0];
if(lbl!= null)
String textInsideCell = lbl.text;