Many official production houses (like Aditya Movies, Shalimar Telugu Video, and Suresh Productions) upload full-length classic and mid-2000s movies for free in high definition.
The following platforms provide extensive Telugu libraries with options for offline downloading: A To Z Telugu Movies -FREE- Download
Most people forget that Tollywood’s biggest production houses (Annapurna Studios, Geetha Arts, and others) have official YouTube channels. Shalimar Telugu Video