Oh, I could find just the founding statement of the project stating it was funded by the “Principal Scientific Advisor” of the government of India https://acr.iitm.ac.in/iitm_in_news/iit-madras-launches-sudh... did you find something different?
replyEdit: it seems you were right. Apparently they have received big donations from ex-alumni including the co-founder of infosys and the founder of Fairfax Financial Holdings. Pretty cool!
The article you linked to itself states;
replyThe centre will power a large-scale multi-disciplinary effort to map human brains at cellular level. It is supported by Infosys co-founder and IIT Madras’ Distinguished Alumnus Kris Gopalakrishnan and his wife Sudha Gopalakrishnan. Since 2014, Gopalakrishnan has been involved in seeding research at the institute at the intersection of neuroscience and engineering.