N Fleet and 5-6 ACC is a good threshold for IN.
For Cruisers, i think instead of N powered Cruiser, India should buy out the plans for SLAVA class Battle Cruisers from Russia and upgrade them. IF N powered Battle cruiser is really planned then it has to be similar to Kirov.
Personally i feel Slava Class (Moskva) suits us better as there is a massive scope of some design augmentations and changing of more modern armaments. See this below
{1000
We can do few tinkers like
1. Replacing S300P with S400 triumf. Even with S300 the range provides us an awesome coverage -64 such missiles in 8x8 config
2. Replacing P1000 supersonic with at present Brahmos (later needs longer ranged brahmos to have similar range). Also can be checked if Shaurya can have Anti Shipping capabilities. With lower warhead size of 180kg and a range of 1900 kms, if we could design Shaura anti ship variant we are looking at a very high caliber missile. We can also look at subsonic Nirbhay fitted into this role. The advantage of K15 variant if we can develop is range and speed over Nirbhay.
The P1000 missile length is 11m and width of 0.88m . 16 such missiles in 8x2 config is there is Slava.
3. OSA -M SR SAM has space for 20x2- 40 such missiles but specs are length of 9m, width of 2.75 m . Barak 8 length is 4.5m and width of just 0.54 m implying we can fit at least 3-4 barak 8s in place of 1 heavy OSA-M (weight 17 tonnes old technology). This implies we may be able to place approx 120-160 barak 8 SAMs.
1-2 such battle cruiser per CBG and few more for western and eastern command and you have another BMD which is floating and is heavily defending types.
Of course we can do more customizations...
Slava being an old design platform should not be too costly for blue prints and since most of the armaments is almost readily available, we can start building it and make quite a good number in 10-12 years.