Core sector industries had grown by a mere 0.4 per cent in the same month last year.
Petroleum refinery products and coal production grew by 20.3 per cent and 10.9 per cent, respectively in the month under review. Steel output grew by 5.9 per cent. Fertiliser and cement output increased by 2 per cent and 6.8 per cent, respectively.
"The modest growth in October was on account of double digit growth witnessed in the production of petroleum refinery products and coal," said an official statement.
This is the highest growth rate registered by core sector industries since February, 2012 when the expansion was 6.9 per cent.
Notably, 6.5 per cent growth in infrastructure industries is in contrast to the decline in GDP growth in July-September period of this financial year (2012-13).
Economic growth slipped in the July-September quarter to 5.3 per cent, raising fears that the slowdown may pull down the annual growth rate to decade's low level.
In October, growth in electricity generation, however, slowed to 5.2 per cent. Natural gas and crude oil production contracted by (-) 14.9 per cent and (-) 0.4 per cent, respectively.
During April-October, the core sector growth has slowed to 3.7 per cent from 4.3 per cent in the year-ago period.