IGNOU at present is not offering MSc (Computer Science).
Similar other courses offered by the university are :-
1. MCA (Eligibility : Any Graduate from a recognised university. However, students who have not pursued maths as a distinct subject at 10+2 are required to pursue and pass the CS-60 course concurrently).
2. MSc (Mathematics with Applications in Computer Sciences) - Eligibility is Graduates with a major, or honours in mathematics with at least 50% marks in aggregate. or graduate with a BA/BSc degree with maths as one of the three main subjects with equal weightage, having at least 50% in aggregate and 55% in aggregate in the mathematics courses).
3. MS (Software Technology) : Eligibility : Science Graduates with recognized bachelors degree (bca/bcs/biti/Bsc in IT etc of minimum 3 years duration with focused education in IT (with minimum 55% marks at the graduation level).
In your case you can pursue MCA (but only after MBA since two degree programmes cannot be pursued concurrently) by opting CS-60 course.