all right let’s see
1 represented 2 while taking part in 3. This was 2’s first appearance in 3. 1 also won 2’s first medal in 3.
The answer is Norman Pritchard, the first “Indian” to win a medal at the Olympics (first person representing an Asian country actually). This was also India’s first entry into the Olympics.
The IAAF recognizes Pritchard as an entry from Great Britain but the IOC still credits the 2 medals to India