You can view the Ayatul Kursi with Sinhala Translation provided by The Quran Institute.
Allahu laa illaaha illaa huwal hayyul qayyuum. Laa taakhuzuhu sinatunw wa laa nawm. Lahu maa fis samaawaati wa maa fil ard. Man zal lazee yashfa’u indahoo illaa bi iznih. Ya’lamu maa bayna aydeehim wa maa khalfahum. Wa laa yuheetoona bishay’im min ‘ilmihii illaa bimaa shaa’a. Wasi’a kursiyyuhus samaawaati wal arda wa laa ya’ooduhu hifzuhumaa wa huwal ‘aliyyul ‘azeem. ayatul kursi in sinhala pdf
Regular recitation is often associated with inner healing and a sense of serenity. You can view the Ayatul Kursi with Sinhala