All societies of Asia were at a lower level of civilisation as compared to european societies . Hence according to this theory , the british rule represented all the aspects of progress and civilisation . In other words , the period before british rule was one of darkness . Can this concept be acceted today ? why/why not?

No, the concept that Asian civilizations were inferior to Western ones cannot be accepted today. This is a highly racist idea that was prevalent during the 18th and 19th century. But such ideas are regarded as highly racist today. All civilizations had positive and negative features and no civilization can be regarded as superior or inferior to others.