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
Download NBC 2016 – Volume 1 & Volume 2 [PDF]
IS 1893-2016 [Criteria for Earthquake Resistant Design of Structures]