The only way to add radio buttons in SSRS is to have a parameter that is of data type "Boolean". Obviously you would then only be able to have 2 values of either "True" or "False" (or possibly 0 & 1) for that parameter. Then you could show top 2 or top 10 data based on the value this parameter in the "Visiblity" property. Alternatively, you could attempt to modify the sql with the parm, but simply having 2 data sections that you toggle would be much easier and more flexible IMHO (you would also need 2 datasets).