As discussed in my previous article regarding Crystal Reports (CR) for Visual Studio, CR is now a separate application that needs to be installed before you can use it in Visual Studio. CR is not included in any released of Visual Studio starting from version 2010.
So in order to use CR for Visual Studio 2015, all you need to do is download the right version for this.
CR comes with different version and the best version and works best for VS 2015 are from Service Pack 16 to 20.
I advise you to download the latest Service Pack of Crystal Reports Developer Edition for Visual Studio 2015.
To install CR please visit How to Add SAP Crystal Report in Visual Studio 2015.