Not that I like TCS or Infosys, but why does everyone appear to hate them so much? If most organisations appear to go with them, is it because they lack market options at what they offer?

On the other hand ,Wouldn’t some other govt sub-org like CDAC etc might get to build this via NIC or whomsoever supervises this?

In one word, cost! But you get what you pay for and it shows in the quality of the work. The engineers are just fresh out of college and are given titles like junior dev or senior dev rather quickly to retain them. This combined with fake resumes compound the problem where a solution to any problem is simply reboot the computer. CDAC/NIC are even worse -- just go see the state of some state-run sites, they've got people that are stuck in the past, can't be fired and won't change things because hey, why change things when you will get paid nonetheless!

I have read somewhere that this software will work in perfect harmony with Aakash tablet: another state of the art government project.

Our beloved PM sending messages via 'Raamdoot' messenger on Aakash tablet will set the tone for entire bureaucracy.