For data science coding, websites such as HackerRank, LeetCode Online Judge etc. could be considered for preparation. The SQL tutorial can be considered for preparing the questions related to data management bit. Apart from that, the e-book on machine learning using Python and the solutions on GitHub can be referred for preparing questions in machine learning & data science. And, finally, Udacity can be referred for statistics related preparation as well.
Students can also refer onlinecoursetutorials.com, Analytics Vidhya or even the blogs published by Board Infinity for better preparing for data science interview.