MCA

You are a BCA student. If you are interested coding, progamming, etc. then you can go for MCA. If you are interested in the management field, go for MBA (IT).

For MCA admission, the first preference is given to ranking in entrance exams i.e. PGCET or KMAT. There are some colleges offering MCA on merit basis. You can try in BITS. Else Pune or Bangalore is a good option.

Check out the link given below:
http://entrance-exam.net/forum/general-discussion/possible-join-mca-after-doing-diploma-computer-engineering-1032741.html

Suresh Gyan Vihar University is a good and valuable university recognised by the govt. If you want to do MCA from distance, you can apply for SMU (Sikkim Manipal University) or IGNOU!
Good luck!

Average salary would be between 2.5 to 4 lpa. Companies that visit the center are as follows:
TCS, Evosys, Streebo, Elite Core,Zensar and many more.

If you are able to clear or reappear in subject in which you have failed in 5th semester before start of MCA then you are eligible for seeking admission in MCA. Some universities might give you provisional admission subject to clearing BCA by their published date of submission of documents.

10+2 with maths as one of the subject and degree with maths and any B.Tech course or BCA.

Surely, you can. If you have sound technical knowledge, after 1 year of professional experience companies focus more on your work then your marks in a particular course.

Nirma is undoubtedly a better option in terms of faculty and placements.