We are travelling from Colombo to Galle in April. We would like to take a train, either Exporail or Rajhastani.
Are there any first class carriages operating? Can we prebook?
A Google search leads the visitor to the website of Sri Lanka Railways (SLR).
A simple search performed for 1st April from Colombo fort to Galle shows 10 results:
We have an existing thread that answers your second question: How to book a train ticket in Sri Lanka in advance?