"If my ex-boss JRD (Tata) had been around, he would have punched me in the gut because I have a paunch," says T R Doongaji, Managing Director of Tata Services Ltd, patting his tummy as he walks me around the Tata's Century of Trust exhibition at the Indian Institute of Science, Bangalore, on Saturday. I look at his almost flat waistline and smiled.

"Did you know JRD was a weightlifter?" he asks, as we walked along side by side. "His ideal male figure was one who looked like the Roman statues in museums. He was a great fitness buff. At age 60, he could do 50 push-ups! I dare you to do even 20 at your age, now." I walk on quickly before I am forced to admit my own inadequacy.

• The Tata Legacy: A slide show

A guided tour of this carefully crafted exhibition by a man who has worked for the Tata's for 35 years now was a special experience, as every picture or display triggers off a memory for him. "I have been like Nandi (Lord Shiva's devoted bull) in a Shiva temple, passionately in love with his God, who, in my case, was JRD," he reminisces.

This exhibition has been designed by architect Subir Mazumdar, who also works for the Tatas, to showcase the entrepreneurial spirit of three of the great Tatas -- Jamsetji (JN), JRD and Naval. This year is, by coincidence, the 100th since J N died, and the 100th since the other two were born.

"Jamsetji never lived to see his third son," says Doongaji regretfully, as we walk into the exhibition hall. "Do you know who I refer to? It is this place, the Indian Institute of Science! He actually left a third of his fortune for the creation of this place, and directed his sons to pay even more, if it was required!"

It was quite appropriate that the exhibition was held at the Entrepreneurship Centre of the Society for Innovation and Development of the IISc. Spread over a carpet area of 6,000 square feet, the exhibition has three key elements. It will be open to the public in Bangalore for a fortnight, after which it will travel to seven other cities: Hyderabad, Chennai, Mumbai, New Delhi, Pune, Jamsehdpur and Kolkata, for 15 days each.

"I wish we had another 1,500 square feet more," rues Doongaji.

There is a central area that displays the core values of the Tata Group, through which there is a walkway. To its right are alcoves showing various segments of the history of the Tatas. On the right is a long, lighted panel showing panels of Indian history. The idea behind this is to show how closely the lives and times of the Tatas have been linked with the evolution of India.

The exhibition is hi-tech and interactive. Every section has video clips displayed on touch screens, pertaining just to that particular dimension of the Tata business: such as Tata Iron and Steel or Tata Textiles, et cetera. Large video screens also have continuous displays of audio-visual footage on those very subjects.

'Chhooaa hai humne, har dil ko chhooaa hai. . . (we have touched, touched every heart)' the melodious notes of a song float out of the audiovisual alcove that forms a part of the exhibition. Its ceiling is designed to look like a starry night sky. Huge mock steel girders hold up this make-believe sky.

Standing under it makes you feel as if you are in a planetarium with a short sound and light show going on. Four screens display a film based on a small, patriotic poem, again linked to Tata businesses and employees. Each screen shows a different picture, and the overall impact is quite moving.

The Indian history display begins with the Sepoy Mutiny of 1857, goes on to the foundation of the Indian National Congress by A O Hume in 1885 and C V Raman winning the Nobel Prize in 1930.

The Tata alcoves begin with one that recreates Jamsetji's birthplace in Navsari, near Surat in Gujarat. "Jamsetji was born to Parsi priests in Navsari: please come to Gujarat some time and I would love to show you my founder's old home," says Doongaji, as we walk on into the space made to look like a small room with barred windows.

Jamsetji discovered that the black soil of Nagpur produced excellent cotton. But, way back in the late 1800s, Nagpur had no textile industry. When Jamsetji went to Manchester to find out why, he was told that Nagpur's weather was just not suitable as it was too dry for the textile industry. "So he said, alright, I will bring the Manchester weather to Nagpur," explains Doongaji. Humidifiers were brought into an Indian textile plant for the first time and Tata Textiles was born.

"The Taj Mahal was built by an emperor for the love of his queen," said Doongaji, as we proceed into another beautifully built alcove lit by a large, sparkling chandelier. The banner at the entrance read 'The Grandeur that is the Taj.' "The Taj group of hotels was built by a businessman for the love of his country," adds Doongaji.

He narrates the incident that motivated Jamsetji to build the first Taj hotel. The great Tata took some foreign visitors to Majestic Hotel, then one of the best hotels of Mumbai, only to be denied entrance because he was an Indian. The foreigners were greatly embarrassed and did not go in either, but Jamsetji simply resolved to build a hotel that was even finer, and which would not discriminate against people on the basis of colour or race.

Doongaji has similar, if not such, inspirational stories, to tell about the other Tata companies. Tala Iron and Steel Company, for example, was set up at a time when nobody believed that Indians could make steel. British nobleman Sri Frederick Upcourt even said in disbelief: "Do you mean to say that Tatas propose to make steel rails to British specifications? I will undertake to eat every pound of rail that they make, if they do that."

The Tatas not only managed to make steel, but supplied 1,500 miles of rails to the British in 1914. Doongaji pointed out that in World War-II, British tanks were called Tatanagars. Now, ISRO's launch pads are made of Tata steel. So was the Howrah Bridge of Kolkata.

Not only that, Tata steel continues to be a rare company where not even a single man day of work has been lost to industrial unrest. "In fact, you can say that the civilised part of Bihar is all concentrated around Jamshedpur," jokes Doongaji.

Tata Chemicals. Tata Tea. Tata Motors. Many companies, all successful, driven by the same core values. "Nothing worthwhile is ever achieved without deep thought and hard work," says a panel quoting JRD Tata at the exhibition. "No success or achievement in material terms is worthwhile unless it serves the needs or interests of the country and its people, and is achieved by fair and honest means."

A section of the exhibition called 'Returning Wealth to Society' lists the numerous Tata institutions that are completely devoted to research, medical help, education and so on.

"Most businesses do things for society after they start making profits," says Doongaji. "The Tatas set up businesses to help society. Tata Sons, the holding company for the Tata Group where much of the profits of the Tata companies go, has its major share owned by the Tata Trusts.

Towards the end of the exhibition is a picture and a quote from Ratan Tata, whom Doongaji describes as the 'new icon' of the Tatas, who has achieved a lot in the 12 years that he headed the Tata empire.

"Success at any cost is like an unseasoned dish, it will not taste good," Doongaji repeats something that Ratan says.

The Tatas now have companies in seven sectors: consumer products, services, chemicals, communication and information systems, materials, energy and engineering.

The turnover of the group for 2002-2003 was $11.21 billion. Sales amounted to Rs 55,000 crore. Five per cent of the total exports of India came from the Tata companies.

The group is responsible for creating 2.4 per cent of the India's GDP. Three per cent of the tax collected in the country comes from the Tatas.

Indeed, the JRD legend is something to celebrate, commemorate and exhibit.