He asserted it was a prudent decision to move out the Nano car project from "hostile" Singur in West Bengal.
Participating in an interactive programme organised by the Ladies Study Group here, Tata said there was "countryside underdevelopment" in Kolkata with "not much signs of industrial development".
He said it was a prudent decision to relocate the Nano car manufacturing unit from Singur to Sanand in Gujarat following sustained agitation, led by the Trinamool Congress supremo Mamata Banerjee.
"In hindsight, it was prudent given the circumstances, but it had very high negative cost to us. When we launched Nano, we created a global excitement putting India on the world map of being able to produce a $2,500 car which many said was not possible. We had orders for about 300,000 cars and a waiting list of close to two years," said the former chairman of the conglomerate.
"In the time we lost in relocating, much of the excitement died out with some disbelief that there was any such product, disbelief that such a product would ever come and gave our competitors a chance to bad mouth our product."
"In hindsight, it was prudent because we could not operate in a hostile environment. On the other hand, we did lose the excitement in the product that affected its long-term marketability," he said.
Talking about the city to which he returned after two years, Ratan Tata claimed there was commercial and residential development but not much industrial development.
"Certainly there is unbelievable change in terms of buildings and development, but it still looks like a countryside underdevelopment."
"There is a great deal of movement, both commercial and residential but you don't see that much signs of industrial development," added Tata.
He also said a government has to be supportive of industrial growth, free of any bias to any group or another, for industry to grow in any state.