This is an article from a website with no prior publishing history, no author information, and no source documents. Some dubious staments too, how does this random web writer know about the seeker performance of Akash-NG?
Well maybe he does. Maybe he actually has military connections or MIC connections. Who cares. Multiple seekers is relatively common.
What's surprising with India is that they want to upgrade the Akash rather than develop or purchase superior medium range AD. MR-SAM is being developed but no need to spend on Akash then. Just finish the MR-SAM.
At the moment the Spyder the the only credible short range AD with Akash serving mid range and planned S-400 delivery to serve as long range with some overlap in short and medium depending on the package deals.
Akash is too antiquated a design. Ignoring the rest of the system, the missile is extremely low energy (under Mach 3) and of course medium ranged. Its design is also very blundered.
A ramjet sustained mid range missile?? errrgh no wonder the Soviets didn't use their original much and replaced it pretty quickly. If you want to bother with the added complexity and cost of ramjets, then make it much longer ranged. Ramjets also mean much slower speeds (after boost) than rocket and especially multi-stage rockets or multi-pulse/ throttle-able. Unnecessarily complex and expensive propulsion that is inferior. No one else uses ramjets for surface to air... especially short to medium range. It's stupid.
Ramjets typically reserved for air to ground or anti-ship/anti-surface. They're not hard to that complex but surely add to the complexity and cost since the Akash also uses a rocket motor to boost the missile.
So why upgrade Akash when they are working on MR-SAM. The quick reaction SR missiles are to complement the Spyder. Can't Barak medium range missiles be worked on to make it suitable for land? Make their own land based Barak-8. Complement with MR-SAM. Much better than modernised Akash. S-400 covering the long range layer.