Rubuta ci gaba don wannan sakin layi - Harshana ya sami lambar tagulla a cikin rukunin shekaru 7 a gasar zakarun Asiya ta 2009 da aka gudanar a Sri Lanka. Ya kuma sami lambar zinare a cikin rukunin shekaru 11 a Gasar Cin Kofin Duniya ta Makarantun 2014 da aka gudanar a Brazil. An ba shi lambar yabo ta Candidate Master a shekarar 2015. Ya sami lambar azurfa a cikin rukunin Under 13 a Gasar Cin Kofin Duniya ta Makarantun Duniya ta 2016 wanda aka gudanar a Sochi, Rasha. Ya kuma lashe lambar azurfa a cikin rukunin Under 15 a Gasar Chess ta Duniya ta Makarantun 2018 wanda aka gudanar a Albania. Ya kuma lashe lambar zinare a cikin rukunin Under 16 a gasar zakarun Commonwealth ta Chess ta 2018 wanda aka gudanar a New Delhi. A wannan shekarar, an ba shi lambar yabo ta FIDE. Ya kuma yi gasa a gasar Olympics ta Chess ta 43
wanda aka gudanar a Georgia a 2018 inda ya ci maki 6 daga wasanni 10.