One of my friends studies at IIT Dhanbad, and according to him the coding culture of IIT Dhanbad is developed and good. The following points are based on his experience at IIT Dhanbad:
Therefore, if you are thinking to join IIT Dhanbad then you can go for it. It has a great coding culture. Also, the institutes organize various coding events and competitions for students all around the year which helps them acquiring a good knowledge of it.