The name "Shantaram" really doesn't come up all that often in the novel Shantaram, which is kind of strange since, you know, it's the title. The name comes into play when Lin, who is actually using the false name Lindsay Ford (we never learn his real name), meets his friend Prabaker's mother. She thinks that he ought to have an Indian name, and calls him "Shantaram, which means man of peace, or man of God's peace" (1.6.69).
The title is a little ironic, given that Lin's life is anything but peaceful, but the experience in the village in particular and India in general do lead Lin to a new kind of peace. He makes peace with his criminal, painful, violent past, and seems ready to face a new future in his new, adopted country.