All the data on party numbers and alliances comes from the Election commission, news reports and the occasional wikipedia entry. :)
First came up with the idea for this at a Huffington Post hackathon after the elections in March 2017. Guneet Narula of Datameet and I even worked on a calculator to predict Rajya Sabha seats, we put out an alpha version, might come back to it soon.
The slideshow is kind of designed with mobiles in mind, but should look fine on desktops too.
A detailed illustration of how the Rajya Sabha elections are done and how counting takes place is available in this Election Commission handbook. Other official explanations of the elections are available here and here, but the handbook has the most exhaustive explanation.
If you want to know how I analysed the data, the ipython/jupyter notebook I used is available in the repository. It's commented, don't know how readable the code will be to someone else, but you're welcome to have a look.
The image for the Rajya Sabha chamber used in the first slide was taken from a photo gallery on the Rajya Sabha website.