Do I need data if I'm enjoying my dual citizenship? I was born to Indian-American couple. Let me clarify. If you ask about the most common surname here in India, it's best to go with 'Singh'. If you ask about last name, which is not the surname for Indians, every other person attached kumar or Kumari to their first name. Like Rohit Kumar, Rajkumar, rajkumari, mohan kumar, nidhi Kumari. Kids in schools are encouraged to adjoin 'kumar and kumari' to their first names in place of their surnames because of deep rooted castism and practice of untouchability.