The Cochin University of Science and Technology (CUSAT) doesn't have a single, universally agreed-upon rank. Different ranking agencies use different methodologies and produce varying results. Therefore, there's no definitive answer to "what is the rank of CUSAT?". You'll find different rankings depending on the source (e.g., NIRF, QS, THE). Look for rankings from reputable sources to get an idea of its position relative to other universities.
CUSAT is a single university, not a collection of colleges. It has various departments and schools within its structure, offering different undergraduate and postgraduate programs. It doesn't have "colleges under it" in the same way that a state university system might. The different departments and schools function as part of the main CUSAT entity.