in 4th sem, if you get suppli in 4 subjects, then you'll get year lag... That means in 2nd year, you got a total of 5 supplis... BUT if you get suppli in 3 subjects in 4th sem i.e. total 4 supplis in 2nd year, you will get promoted with XP grade... You'll have to clear third sem's suppli in 5th semester and 4th sem's suppli in 6th sem... i'm 100% sure... personal experience...