Hey Sonali,
MCA is  a post graduate Information Technology  Course. The duration of Master of Computer application is 2-3 years depends upon the University.
MCA Eligiblity:-
1. Any graduate who has passed or appearing for the final year degree examination in any discipline( science, commerce , arts or any approved University) is eligible to apply.
2. Candidate must have maths as a subject in their 10+2 course or any one year of Graduation. BCA qualified  candidates can also pursue MCA.
3. The qualifing Exam must be passed with 50% marks.

The course emphasis on latest programming languages and tools to develope better and faster applications BCA makes a base while MCA adds a specialization touch.
Some of MCA specialization:-
1. Application Software
2. Internet Working
3. Hardware technology
4.Trouble shooting
5. Networking