In the sentence "He told about a common man who was accosted by robbers and left by the road to die," the word "told" functions as the main verb.
The subject of the sentence is the pronoun "He," a singular masculine pronoun in the nominative (subject) case.
"Told" is the main verb of the sentence. It is a singular verb in the simple past tense, meaning that it refers to an action performed in the past. It is in active voice, because the person performing the action ("he") is the subject of the sentence.
The verb "to tell" can be either a transitive verb taking a direct object or an intransitive verb. In this sentence, "told" does not have a direct object but is followed by a preposition; therefore it is being used intransitively.