For true exclusive unreleased masters (ProRes 4444 files), private trackers like AvistaZ or DesiTorrents sometimes host Blu-ray remuxes. However, these are often ripped from 4K Blu-rays and upscaled. Downloading copyrighted material without payment is illegal in most jurisdictions.
Finding true 8K content requires specific platforms that support such massive file sizes and high bitrates. 8k bollywood video songs exclusive download
If you own the original Blu-ray or a high-bitrate 1080p/4K file, you can use software like to upscale it to 8K. This is the most reliable way to get an "exclusive" file tailored to your hardware. The Future of Cinema: The Rise of 8K