I don't understand why we are not investing in need for cruisers for Indian Navy.
Couple things to consider here.
In the traditional Cold War sense of classifying surface warships (which is no longer relevant for most navies), a Cruiser is a large warship designed primarily around anti-air warfare (for defence of the battle group/fleet) while a Destroyer is a smaller warship designed primarily around surface warfare and/or anti-submarine roles.
This differs to a great deal between navies. For example, the UK Royal Navy which doesn't have any cruisers uses its Type 45 destroyers as the principle anti-air warfare ship while relegating ASW/surface warfare role to frigates like Type 23 (or the Type 26 in future). Australian Navy will be following a similar trend (Hobart class AAW destroyers and Hunter class ASW frigates).
Whereas the US Navy which doesn't really have any ocean-going frigates that work in a CBG, resorts to using Ticonderoga class cruisers as the AAW component of a CBG while the Arleigh Burke destroyers take care of a multitude of roles, including the likes of which are performed by frigates in the navies of UK and Australia.
That said, as I already replied to a previous thread you started (about next destroyer class of IN), the Project 18 NGD is estimated to be a 13,000 ton warship which puts it in same league as Type 055 and new Zumwalt class. That is already much bigger than any cruiser like the Tico and slightly more than Slava class battlecruiser.
What more do you want? The only cruiser bigger than that are going to be Russian Kirov class (nuclear powered, 28,000 tons). Even the US is not building warships of that caliber anymore, so why would we or China do it?
Case in point, there is not much to classifications. Even China considers the 055 as a destroyer, as does US (Zumwalt is regarded as DDG), and India too will be following similar path. Project 18 is already called NextGen
Destroyer (NGD).
Any of those 3 ship types can easily be regarded as Cruisers in the traditional sense - but the very fact that USN, PLAN & IN regard them as Destroyers shows that there is not much meaning to the term Cruiser anymore.
We have ambition to control India's Ocean by 2050 and for that we must needna new powerful class of heavy weight Cruisers to tackle is T and chinese 55(A)
P-18 DDG will afford us that capability.
China is going to build around 48 T55 so we have to invest in cruisers as well.
Highly doubt that. They don't even build that many 052Ds so building four dozen 055s is fairly a stretch even to imagine. I think current plans call for about half dozen. That could become one dozen sometime in future.