How to go to trivandrum from cochin airport ( i will be reaching cochin by 5 PM)?

cheap and fast

if you want to continue your journey immediately, you can catch Kerala State Transport bus to thiruvananthapuramm which will reach you by 5 hrs. If you want to travel by train, come to Ernakulam, which is near to cochi and catch the train, which will also reach you by 5 hrs. if it is express train.

From nedumbasserry to Thiru vananthapuram by road (superfast) KSRTC is cheap and fast.

take a ditrect flight to Tvpm bypassing kochi..

easiest way is to take a flight from cochin airport to trivandum but not cheapest
you can get express KSRTC buses and is the cheapest(around 145 Rs per passenger)
You can get deluxe KSRTC buses which is little expensive than regular express but more comfortable (around 175 Rs)
Can get Taxi which is about 2800 to 3500 rupees
if its for 2 passensgers or less Flight is a good way too( if u got good deals)
good luck with your trip ENJOY

Best go to the nearest railway station Alwaye might be more convenient from the airport and get a night train from there to
Trivandrum but you might have problems getting a berth
reserved.The train will be in Trivandrum early morning.For
information on trains go to www.indianrail.gov.in and I think
its possible to book online in advance if you have the time and patience if not get somebody in India to do the
reservation.The overnight train will cost you about Rs 200