IS 456:2000 is the Geeta for civil engineers and structure designers in India. IS 456:2000 got its 5th amendment in July 2019.
You can download this IS 456:2000 amendment no.5 July 2019 [pdf] with this link.
You may also like to download the following codes.
SP-16 [PDF] Download
IS 456:2000 Plain And Reinforced Concrete-Code of Practice(pdf download)
IS 10262-2019 [PDF] Guidelines to Concrete mix design