Option 1 -> SARAL is an Indo-French satellite for oceanographic studies, not amateur radio services.
Option 2 -> SWAYAM is India's online education platform, not a satellite.
Option 3 -> JUGNU is a nanosatellite by IIT Kanpur primarily for earth imaging, not dedicated to amateur radio.
Option 4 -> HAMSAT (HAM Satellite) is specifically designed for amateur radio operations.
Hence, Option 4: HAMSAT -> HAMSAT (HAMburg Satellite/HAM Satellite) was launched by ISRO in 2005 as India's first exclusive microsatellite for amateur radio operators, providing voice and data communication services to the HAM radio community in India and globally -> correct