RCT means if infection of the tooth involves the root part also or patient has a deep infection then definitely pt need to go for RCT. During Rct the entire part of the tooth pulp will be removed n clean the tooth and fill it with guttapercha points followed by covered with a cap for protection of the tooth. Time depends on the pt condition mostly from 1 hr to 2-3 sittings also. Charges also depends on the condition n location from 2000 to 3500.