Got you, I now understand the question and confusion.
Up to 6.5.2, all releases had a second version number, like 6.5.0.3-4.3.0.4. Starting 6.5.2 that second version number was left away, so you only see the first part.
For the IAP-103, you probably looked at the End of Life page, which for the 103 mentions: Instant 4.2 *. Then the asterisk (*) states under the table: Instant 4.2 with full feature support, Instant 6.5 with DPI disabled.
So you can run the IAP-103 up to (and including) Aruba Instant version 6.5.x. If you run a version 6.4/4.2 or below you can enable deep packet inspection, which powers AppRF. On later version 6.5.x or 4.3, the AP still is supported however without the DPI. This has to do with memory or CPU that could no longer fit the full feature set on the 103 hardware.