You're looking for a report on downloading Grand Theft Auto: San Andreas for the PSP, specifically a free download with a 100mb file size. Here's what I found:

The download size for Grand Theft Auto: San Andreas on the PSP varies depending on the region and platform. However, I found that the game typically requires around 912 MB (935,936,000 bytes) of free space to install.

As for a free download with a 100mb file size, I couldn't find any reliable sources that offer the full game for free with such a small file size. It's unlikely that a complete game like Grand Theft Auto: San Andreas would be available for download with a file size that small.