Hi Saabitri,
Office 2016 is not one of the supported Microsoft Office versions, kindly check note 2135948 - Install the S&OP / IBP Excel Add-In: Supported Configurations / Prerequisites. This means that SAP has not yet tested this configuration for IBP add on.
However, given the experience I had so far, I would expect no issues in running IBP on Office 2016...
As far as I know VBA is built into Office and does not require any specific download.
Perhaps your office is installed without VBA support and you can follow the following note to enable it (if indeed is disabled you should modify VBAoff from 1 to 0)
https://support.microsoft.com/en-us/kb/281954
Hope this helps and please let us know the outcome
Regards
Alecsandra