One of my friends is an alumnus of IET Lucknow, and according to him, IET Lucknow has no official dress code in particular. You can wear casuals. At the beginning of the first year, there is an induction program of 21 days where the college suggests having a dress code. But nobody adheres to this rule. However, in the Electrical department, students need to wear shoes instead of slippers.
But just because there is no dress code does not mean you can come to the college wearing inappropriate clothes. It is better to put on presentable clothes that reflect your personality and who you are.