If you have more time, consider adding a visit to the Padmanabhapuram Palace or the Sothavilai Beach. If you have less time, consider skipping Our Lady of Ransom Church, or Kanyakumari Beach to make sure you have enough time to visit Vivekananda Rock Memorial which has the longest waiting time. Don't forget to carry water and sunscreen during the day as it can get very hot in Kanyakumari.