Ratwatte began his education at Trinity College in Kandy, Sri Lanka, where he captained the school's under-13 team.[1] At the age of thirteen his family moved to Mauritius, where he played competitive rugby at St. Nicholas' Grammar School and at the Black River Rugby Club.[2] In 2007 he was selected to represent the national under-18 team during a tour of Madagascar.[1] At eighteen he was selected to play for the Mauritius national rugby union team, becoming the first Sri Lankan national to play for a foreign national rugby team.[2]
Ratwatte completed his schooling in South Africa at the King Edward VII School in Johannesburg. He was successful in completing the Matrix Examination which is equivalent to the Sri Lanka's Advanced Level Exam.
In 2009 Ratwatte played for the Division 'A' rugby union team, Ceylonese Rugby & Football Club in the Sri Lankan Rugby League competition before transferring to the Up Country Lions in 2012[3] Following the demise of the Up Country Lions he signed with Kandy SC.