Hii,Rau’s IAS enjoyed great prestige many many years ago. I guess nearly 15–20 years back. One of my school teachers had attended Raus and held very high regards for the institute. But unfortunately it is all past now. Rau’s do not possess good teachers, do not provide quality materials and hence, has gone in oblivion. Just stroll down the streets of ORN or mukherjee nagar and you will hardly find any photo copies of Raus classroom notes. WHY? Because they do not suffice the purpose any more. Also, the location of Raus classes is yet another issue. It is away from the so called IAS HUB providing necessary study materials.

Vajiram is the best. NO doubt. No wonder why it attracts thousands of aspirants every year for admissions. Sriram is close second. And the reason why vajiram scores high is the excellent faculty it provides. Teachers like Mr. Ravindran are class apart. No other coaching notes can match the level of his classroom dictations. Also the famous yellow books of vajiram need no introduction. But yeah, the fees is exorbitantly high. But so is of sriram. 

Hope,this information helpful for you.Goodluck.