synchronising of 12 MW pumping station

No.

11 kV soft-start? Did not know that they were made that large.

Synchronizing a pump motor? With what?

Exactly. Where does synchronizing come in?

No idea what "FSC" means, it is not an industry term that comes up in any searches. FCMA is a motor starting technology being promoted by a single manufacturer in India who seems to think they have invented something entirely unique. In reality though, it is just a rebirth of a "Magnetic Amplifier" or "Mag Amp" motor starter that was built by the likes of GE and Westinghouse for a number of years until the 1970s, but which they have both abandoned as impractical in the face of solid state technology.

If you are in India, you will have support of that one company (for as long as they survive), but elsewhere in the world, you will be hard pressed to find support since without a large installed base, there are very few people who will even recognize what it is, let alone be able to fix it if it breaks.

At 11kV, your choices of soft starter technologies of any sort are limited, so I suppose you are always going to be at the mercy of whomever you can find to bid it, but if it were my money, I would call someone such as Siemens who is going to be around for a while.