On the BIS website, you can search for "IS 456" and download the PDF version of the standard (with amendments) after purchasing or registering for an account.
https://bis.gov.in/
The latest amendment to IS 456 was published in 2017. Here's an overview:
Is 456 Latest Amendment Pdf -
On the BIS website, you can search for "IS 456" and download the PDF version of the standard (with amendments) after purchasing or registering for an account.