Ionic cordova platform add (ERROR), How to solve this issue?

Hi,
Can someone tell me how to solve this error?
This error coming after this command -
ionic cordova platform add android

After doing this, there is no change in my project, i.e. not created any file/folder in my project.
Please give the solution for this issue.

Try to use this version of android platform

ionic cordova platform rm android
ionic cordova platform add android@6.3.0