Hey Ashish, You will have to take a flight from chennai to port Blair .. flight duration is around 2.30 hrs .... And for the question of how much it will cost to you ... including Havelock Island, port Blair , and Neil Island ... it will cost you upto 30-35k including flights also ... coming to the part of itinerary here it is for you :- Day wise itinerary for you in andaman and Nicobar islands :- Day 1 and 2 :- Andaman jail also called as kalapathar jail Corbyn's cove beach for Sunset Marine museum on the way to wandoor One more marine national park on the way to chidiya tapu beach chidiya tapu is a best for one more sunset You also have ross island and North bay islands for snorkelling and scuba diving Day 3 and 4 :- Havelock Island and Neil islands ... Kalapathar beach Radhanagar aka Asia's best beach elephant beach for which you can take a Trek .. natural bridge in neil island Day 5 :- if you have missed anything in port Blair then you can covet it on this day and take your flight back home ... Here are few photo blogs of my last visit to andaman and Nicobar below :- https://www.google.com/amp/s/www.tripoto.com/trip/admirable-dawn-and-dusk-in-andamans-5bdb05b65f505.amphttps://www.google.com/amp/s/www.tripoto.com/trip/calmness-redefined-havelock-5bdd7fc41e273.amp Happy Travelling Bro !!!