If you are planning to drive it takes 11 hours to reach Kanyakumari. Other forms are reaching by train or by bus. You need two days to spend in Kanyakumari. Starting with Kanyakumari beach sunrise Visiting Thanumalayan temple, vattakottai fort is 5 km away. Tsunami monument, view tower, Gandhi mandapam, if possible you can cover wax museum. Evening definately stop by sunset beach, sanguthurai beach and reach city market to eat and shop. Next day plan a ride to Vivekananda rock memorial, Thiruvalluvar statue, Kumari Amman temple and proceed either towards Padmanabhapuram palace or thiraparappu falls. In Trivandrum you have lots to explore besides the palace and near the falls there are activities like boating and swimming with local cuisine to taste. From Kanyakumari Rameshwaram is 5 hours away. Same you need two full days to explore. Starting with Rameshwaram temple Jatayu theertham Agni theertham Villoondi theertham jada thirtham are must visit spots. Evening you can cover aquarium, Ariyaman beach sunset, Abdul Kalam house and bird sanctuary. Next day you can explore dhanushkodi visit the deserted town, small beaches and temples like Thirupullani. You could do a pamban bridge ride and shop a lot. Either you head towards Madurai or Trivandrum to make your return journey to Bangalore.