can anyone tell me how to select lrdi sets in exam? i always select wrong sets and after completing the exam i realize that the set i have left is easy

Have a look at all the sets in the exam. Select the one which you feel is your strong area, for example charts, arrangements etc. Bookmark that question and write down your order of attempt on the rough sheet. Say for instance you look at a test and feel like you need to attempt sets starting from Q1 (4 questions), then Q5 (6 questions), Q12, (4 questions) and lastly Q17 (6 questions) in this order then just write Q1, Q5, Q6 and Q17 is ascending order of attempt on your rough sheet. Spend about 2-3 mins before starting any set to look at the entire section.