Section 6 of Indian Evidence Act, 1872 is based on the English Doctrine of Res gestae.
Section 6 deals with Relevancy of facts forming part of same transaction.
Facts which, though not in issue, are so connected with a fact in issue as to form part of the same transaction, are relevant, whether they occurred at the same time and place or at different times and places.
Res gestae is a Latin phrase which means that forming part of the same transaction. It means that relevant portion of the event which is connected directly or indirectly with the main transaction of the event.
Hearsay evidence is not admissible in Court of law. But, res gestae is exception to hearsay rule.