Aman and Kaushal have written a book jointly and seek to get the book registered in the Copyright Act, 1957 as joint owners. Can they do so?

Yes. Copyrights can be owned jointly. The Copyright Act, 1957, provides that "work of joint authorship" means a work produced by the collaboration of two or more authors in which the contribution of one author is not distinct from the contribution of the other author or authors. If two or more people create a work with the intent that their individual contributions merge into the final product, they will be joint owners of the copyright. The determination of joint ownership is a question of the intent of the participants. Each joint owner can deal with a joint work as if he or she owns the property independently of the other unless otherwise agreed.