I uploaded an .htaccess file, but I don’t see my changes taking effect when I click on the old URL to redirect to a new URL. Do I need to wait a while before it takes effect?
It should work straight away.
Perhaps you should post what you have put in your file to make sure it is correct?
Just this (changed for privacy):
Redirect 301 main/charts/index.html http://www.example.com/main/new/newsub/charts/index.html