Yes, you can take admission in M.Tech Computer Science in IITs or NITs through GATE, even if you have completed your B.Tech in Information Technology and Mathematical Innovation from Cluster Innovation Centre, University of Delhi but there are a few things to keep in mind:

Eligibility depends on GATE paper: You need to appear for the GATE Computer Science paper. If your degree has sufficient CS or IT subjects, you’re eligible for this paper.

Each IIT or NIT has its own criteria: While most IITs or NITs accept related branches like IT, some specific institutes might have particular course requirements. So, check the official brochure of each institute.

Admission is based on GATE score and category: A high GATE score improves your chances, especially for top IITs. You’ll also need to apply through COAP for IITs and CCMT for NITs.

So yes, you're eligible, but always cross-check eligibility criteria of the specific institute during admission time