Section 106 of The Indian Evidence Act, 1872
106. Burden of proving fact especially within knowledge.—When any fact is especially within the knowledge of any person, the burden of proving that fact is upon him. Illustrations
(a) When a person does an act with some intention other than that which the character and circumstances of the act suggest, the burden of proving that intention is upon him.
(b) A is charged with travelling on a railway without a ticket. The burden of proving that he had a ticket is on him.