No, you cannot opt for only Maths exams through NIOS and be eligible for MT CET PCM B.Tech.
You can check out the CAP round 2 cutoff for the different colleges and see which colleges you will be eligible for admission as per the cutoff data.
Dear Sahil,
The computer science branch at Sir M Visvesvaraya Institute of Technology (MVIT) is consisdered to provide quality education to its students. The curriculum is designed to provide students with a comprehensive and up-to-date education in computer science. MVIT's CSE department has a state-of-the-art infrastructure, with well-equipped laboratories and access to the latest software and hardware. The department also has a strong placement record, with students being placed in top companies such as Amazon and Microsoft.