Yes, that is the correct way. I did something similar for my infant son for a trip last month. However, i think it'll be 80k miles from zone 6(India) to zone 2(Indonesia) as per their award
chart for 2 adults return fare. However, one good thing with booking return award tickets in Singapore airlines is that they allow stopover in Singapore. While returning, we stayed in Singapore for 5 days this way. So effectively, you can tour 2 countries with the same ticket.