MCA

Yes, you can apply for GATE. As per eligibility criteria, a candidate must be passed out or in final semester of the M.Sc/MA/MCA course, there is no minimum and maximum age limit for GATE. There are 24 subjects papers in GATE exam and one has required to choose only one from them. As you have comple

In about salary- It depends on the company and your achievement qualification and knowledge.

No, for MCA candidate you must have their bachelor's in IT or CS.

Hi,
You can consider these colleges:
University of Delhi
National Institute of Technology Tiruchirappalli
Banaras Hindu University, Varanasi
Guru Nanak Dev University, Amritsar (Punjab)
Andhra University Colleges of Engineering
Cochin University of Science and Technology
Kurukshetra University.

As the fees is not disclosed by the college, request you to contact the college officials for the same.
Link: http://eng.bangaloreuniversity.ac.in/

KIIT School of computer applications offers two years of MCA Lateral entry program. The eligibility criteria for this program is graduation in relevant discipline. Further your rank is not enough for this program, may please improve this.

There are various MCA government colleges in Gujarat. You can go through this link to find out in more detail:
https://www.shiksha.com/it-software/colleges/mca-colleges-gujarat.

Placements of this college is awesome as this college placements always break their own records and if you look at the records of the last 5 years then you will get to know about the progress of this college and this is only because this college tries it best to bring all the possible companies to

Kindly go through the link below for an article on B.Sc. Neurophysics:
https://www.shiksha.com/science/articles/job-options-after-bsc-degree-know-salary-packages-blogId-13469.