training is a part of wbut curriculum before 4th year... according to wbut syllabus and for better placement and knowledge one should do some training in their own sector as much as possible.. it is suggested to do a 4 weeks of training in total.. one can do it even after 4th sem.. the better process can be-> after 4th sem: 2weeks training(summer) after 5th sem: 2weeks training(winter) after 6th sem: 4 week training(summer)