No, Only DAC cleared it then. Fabrication starts next year (hopefully). Also there is no space in the production facility. So the schedule depends on S4 rollout. (Unless they build a new facility without us knowing).For all you know the hulls may already be in the process of being fabricated. The go ahead was given in 2016 ,IIRC.
Its just impossible to have a new class of SSN in service in 6 years. The series production will probably go on till 2040's.
And where are these next-generation SSBNs? (Which is S5). We don't have anything comparable with P5 as of now.India first studied nuclear submarines in 1970s, first nuclear submarine Charlie class was taken on lease in 1986-89, detailed design for SSN was completed during late1990s with a lot of Russian inputs and then converted it into ad-hoc SSBN which we better know as INS Arihant. And now we're in much better position to deliver next generation SSBNs within 6yrs if need be.
What was lacking was political will to take on P5s to accommodate/shove/push ourselves on their table whether they like it or not, which we did with Arihant, so now it should be smooth sailing..![]()