Science

after BCA you can do MCA which will be quite easy for you .than CS MCA get more opportunity on IT field

if you do engineering from IIT , bit, and nit then you can good job and if you want to study engineering from normal college . then you can get jobs around 1 to 2 lakhs merely . the situation of engineering in our is too worse if you are not doing from IIT , nit like institute. choice is yours.

You can pursue short term courses along with your graduation like Mysql, Operating systems like java,android,etc, Oracle.

In Andhra Pradesh, you still have chances. But, in Telangana, there are common admissions and they may be closing.

There are two options to join space research institutes: (a) Engineering in Aeronautical / Aerospace / Mechanical / Electronics / Metallurgy (b) M.Sc Phyics or Chemistry. You can get entry level jobs with above mentioned degrees. Higher degree in subjects will increase your chances of getting job in ISRO or NASA.

Your query is little confusing. Is your wife currently studying in UK? If yes, then she can consult the university guidance cell for all information about work and settling down there. If not then you should consult some reliable UK consultancy to know all the details about migration as UK currently is not very welcoming in terms of jobs.