I want to add maximize button in infowindow, where on maximize the content also get larger like charts, diagrams etc. Please find below image for example.
when i maximize the size of the pie chart shall also increase.
Which version of the JSAPI are you using? The image looks like the InfoWindow which was used as the default popup window prior to version 3.4 of the JSAPI. If you are using a version later than 3.4 the Popup should be the default and it contains an expand button by default. Here is a sample showing the popup in action: