Yes, Tesseract is used for many Wikisource books, mainly (?) via phe's tool https://github.com/phil-el/phetools/tree/master/hocr / https://tools.wmflabs.org/phetools/
You can search the archives to see some things that have been tried in the past, including http://terese.sourceforge.net/ . There are many repositories with Indic training sets, but I never understood the process to bring them together and make their usage wider.
Nemo