need to see whats the reason of sensitivity cuz RCT treated teeeth shouldnot have Sensitivity or pain if its done properly. Pain can be becuase of infected Gums or bones surrounding the teeth. So whats the cause of pain needs to be examined and confirmed after doing xray of the tooth

Decayed tooth and after RCT can have sensitivity due to hot and cold! Maintain oral hygiene and if possible try to avoid too much hot and too much cold. Futher opinion you can take from dental doctor by going through this link: https://www.hamrodoctor.com/doctor/dr-krishna-prasad-regmi/