One of my friends who used to be a student of Madras Institute of Technology and he said that it was the same case when the discipline of CS was added to the institute.
The college adopted the concept of co-series, which involved the seniors allowing the new students in the CS department and making sure the guidance was equal. This tradition was followed till the time my friend graduated where they had one T-Series and one Co-Series, that is; an IT counterpart. The seniors from automobile engineering might take such a step.
The intake mismatch is a common scenario wherein any given year; there will be a mismatch in the number of people being admitted for a program with previous years. In such cases where the co-series comes into play, a senior might get two juniors on a rotation.