The Bureau of Indian Standards (BIS) continues to refine the "Code of Practice for Plain and Reinforced Concrete" to include modern materials.
Here's a draft paper based on the 2020 amendment to IS 456: is 456 latest amendment pdf
Legally no. However, many small contractors ignore updates. It is risky – insurance claims may be denied if non-compliance is found after a failure. The Bureau of Indian Standards (BIS) continues to