The country witnessed the fastest rate of growth in steel production during March in the last three months at 6.5 per cent to 6.86 million tonne, data from the World Steel Association shows. It may be noted that in January, steel output grew at a slower rate of 3.8 per cent to 6.6 million tonne while in February it contracted 0.5 per cent to 6.2 million t over the year ago period.