No, the government cannot curb freedom of speech in India, because there are far too many people to control. India has a huge population. The people of India watch other nations, such as Americans and Europeans, exercise freedom to say the things they want to. The Indian people demand the same freedoms.
Short of executing everyone who disagrees with yourself, it is virtually impossible to stop people from speaking their minds in this age. With the internet, I can tell people all around the world what I think about something immediately. Unless they shut that down, they cannot stop free speech without causing a serious blow to culture as well as their economy.