Hi,
> I've a dynamic table tha have many radiobuttons and i need to click on a specific item. is there a way to click on a item by index number.
I haven't seen the overall page markup for the given table, but it is quite a common thing for dynamic pages that do not have unique and stable identifiers for web elements, to apply multi-steps approach to get and use required web element.
As a possible example for your case:
-- Assuming, that for the given table you are not looking for just the radio button, but looking for the radio button that is in the right-most column of some row, and another column of this row contains identifying information (e.g. order number),
-- You may search for this identifying information first;
-- Then, using the knowledge of how the page is designed, you should figure-out / calculate the row;
-- Then, for the found row you should find its right-most column and search for the radio button that is within the found cell. (Note, this well might be not a real cell with <TD> markup, but something, that looks like the cell but has different markup. <DIV>, for example.)