Devarshi, Note how "Struts" is spelled. A "struct" is a type of data structure - something else entirely.
It sounds like you are trying to pass a 2D array to an action via an action form? If so, this is impossible to do. The request.getParameter() framework that Struts forms uses behind the scenes doesn't support 2D arrays.
Can you elaborate on the problem you are trying to solve? This will help people recommend alternatives.