The defence ministry has already shortlisted two Indian shipyards and five foreign defence majors for the project, being billed as one of biggest "Make in India" ventures.
The Kolkata-class warship, the first of P15-B stealth destroyers, was launched by Minu Dhowan, wife of Chief of Naval Staff Admiral R K Dhowan, at Mazagaon Docks Ltd.
The 'request for proposal' for the indigenous construction of the six submarines will be issued soon, they added.