The short answer
Copyright normally stays with the architect unless the agreement transfers it; you usually get a licence to build and use the drawings.
Under Indian copyright law the author of the drawings — the architect — holds the copyright unless it is assigned in writing. Clients typically receive a licence to construct and occupy the building, and to retain copies for maintenance.
If you need editable CAD or BIM files, or want to reuse the design elsewhere, agree that explicitly in the engagement. It affects both the fee and the architect’s liability if the design is changed by someone else.
Continue on Architects In India
copyrightCADBIM