Part of it's mission is to study the Martian atmosphere for signs of life. Other orbiters have already detected signs of Methane in the atmosphere which can be an indication of life, although it can also have geological causes. Methane has a very short lifespan of around 10 years, which means that it's production will be recent.
The interesting thing about this satellite is that is cots almost 10 time less compared to NASA's Maven mission.
One of the largest costs when considering space missions is human wages and India's wages for it's Scientists and Engineers will be cheaper than American wages at NASA, but more importantly the reason it was a lot cheaper is because the Indian Space Agency had very specific goals and was very careful in what they chose to study.
With countries having a national interest in sending their own probes to the Red Planet and beyond, it makes one wonder how much money would be saved if a Global Space Agency existed, and countries didn't have to send duplicate experiments, probes and satellites out of "National Interest & Pride" rather than cooperating together.