Indian Post Office Act, 1898
28. Registration of postal articles
The sender of a postal article may, subject to the other provisions of this Act, have the article registered at the post office at which it is posted, and require a receipt therefor, and the Central Government may, by notification in the Official Gazette, direct that, in addition to any postage chargeable under this Act, such further fee as may be fixed by the notification shall be paid on account of the registration of postal articles.