MCA Eligibility

For M.Sc in CA, you must have bsc degree in same field or equivalent.or
B.Tech in IT or CSE or equivalent stream.
Minimum of 50% in your graduation

Hello dear,
I am sharing you the link which will give you all basic idea of the exams from the eligibility, syllabus, exam date and other sorts of information. This will help you to clear all the doubts regarding your upcoming exams:
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/university/national-institute-of-technology-durgapur/exams/amp/nimcet&ved=2ahUKEwi0wqPZ-qPbAhXMeisKHWNIBA4QFjABegQIBxAB&usg=AOvVaw0GFjLYbVUhmpEMJbG-FsR_&cf=1
All the best.

Hello dear,
I am sharing you the link which will give you all basic idea of the exams from the eligibility, syllabus, exam date and other sorts of information. This will help you to clear all the doubts regarding your upcoming exams:
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/university/national-institute-of-technology-durgapur/exams/amp/nimcet&ved=2ahUKEwi0wqPZ-qPbAhXMeisKHWNIBA4QFjABegQIBxAB&usg=AOvVaw0GFjLYbVUhmpEMJbG-FsR_&cf=1
All the best.

Try to solve NCERT books thoroughly.

Yes, you can do it without any doubt. It will be easier for you as you already a computer Science graduate.
NIT (s) ask for maths as a subject in your 10+2 or graduation level. Rest, there are many universities which doesn't even consider Maths as a criteria.

After admission for MCA with lateral entry, you have to give first year exams also with your 2nd year exams. I think, these only differences are there. After completing these two, you have same value of degree.

Please check for your eligibility to apply for MCA (Lateral) admissions from the criteria mentioned below:
Eligibility Criterion:
Eligibility criterion for admission through lateral entry differs according to University. Eligibility requirement for some of the well known Universities is mentioned below. Admission to the programme is based on the scores obtained in qualifying exam as well as in interview. Some institutes such as Shobhit University conduct entrance exam for admission process. Regards.

Most of the universities require 50% for MCA.

You need to appear for MAH-MCA-CET:
Eligibility criteria for appearing to MAH-MCA-CET:
a) Passed with minimum 50% marks in aggregate or equivalent CGPA (45% in case of candidates of backward class categories and physically handicapped) of minimum three years duration in any discipline.
Candidates who have passed BCA, BCS or B.Sc (Computer/information Technology) degree courses are not required to fulfill the requirement of having studied mathematics or statistics as one of the subjects at 10+2 level or higher level examination.
b) Valid score of MAH-MCA-CET conducted by the competent authority.