I applied through college /university. It was a 2 days drive. 1st day-aptitude, in aptitude there were 3 sections quantitative, logical and verbal. it was followed by technical questions of the respective domain you are in. There was 45 technical question and the time allotted was 30 min . all the questions were theoretical yet very tricky. practical knowledge plays a very important role here. power system protection, switchyard elements, and machine are few of the topics. aptitude was not too hard not too easy to focus more on verbal reasoning more than quantitative.