It looks like you’re asking about a feature of the novel by M.R. (Muthulakshmi Raghavan), specifically mentioning KUPDF (a site where PDFs are sometimes shared).
Many novels on KUPDF are uploaded without author/publisher permission. If you want to support the author M.R., consider buying the original book from platforms like Pustaka Digital, Notion Press, or Amazon . ora vizhi parvaiyile mr novel kupdf