I dont know where did the director of IITM get his information from, but in USA, it usually takes 3-5 years to complete your Ph.D. I know lots of friends who have done it in 3-4 years. In all these years here, I have never heard anyone taking 7 years to do it. 6 was the worst I heard, and that too was one isolated case. So I would urge the director not to manipulate facts and come up with better logic for explaining the facts