Computer Science Engineering and Information Science/ Information Technology are different branches though relatable. ISRO during recruitment clearly mentions the branches which can apply under a given opportunity/position. For example it clearly mentions whether Civil, Aerospace, Manufacturing or Production Engineers can apply under a Vacancy meant for Mechanical Branch.

There may be certain vacancies where they relaxe the criteria to Information Science, IT, Data Engineering graduates besides CSE Branch, whereas there might be certain appointments specifically meant for CSE and Specializations.