The contest has started today and it will go on for next one month.
Tom Derrick, the digital curator of the Two Centuries of Indian Print project of British Library, has published a blog post about it on BL website.
BL has also tweeted: https://twitter.com/BL_IndianPrint/status/1371427115850215424
Hello,We are happy to announce that the West Bengal Wikimedians User Group  will run a proofread contest  from 15 March 2021 to 14 April 2021 on Bengali Wikisource in collaboration with Two Centuries of Indian Print project (TCIP)  of British Library.The TCIP project officials are uploading the public domain books under their collection on Wikimedia Commons . From the user group, we are working on the next steps like renaming files, indexing, metadata related work on Wikidata etc. and will be organizing the event.The top five winners will receive T-shirts and/or books from the user group and digital certificates from British Library.Regards,BodhisattwaOn behalf of West Bengal Wikimedians User Group