Crimea decided its own fate. All the world supported Russia; China and India supported Russia.
The international community, including China and India, refused to recognize the annexation of Crimea: see UN GA Resolution A/RES/68/262 adopted on March 27, 2014, on the territorial integrity of Ukraine. China and India abstained from voting. https://www.un.org/apps/news/story.asp?NewsID=47443&Cr=ukraine&Cr1=#.Wci_xmcdiEB
The resolution states that the referendum in Crimea that led to the peninsula’s annexation by Russia “has no validity".
Beijing has not imposed sanctions on Russia, but it has also refrained from backing Russia. China has repeatedly stated since 2014 that "On the issue of Ukraine, China has adopted an objective and just position. We respect Ukraine’s independence, sovereignty and territorial integrity."